LimaCharlie Release Notes: Endpoint Agent

Endpoint Agent 5.3.7

Mon, 24 Aug 2026 00:00:00 GMT

New Features

On Linux, DNS events now report the process that sent the query or received the response, where the kernel supports it (verified on 5.15 and newer); older kernels keep delivering DNS events without a process ID. DNS events on Windows and macOS are unchanged.
On Linux, kernel telemetry — file, process, socket, network and DNS — now loads on kernel 5.4, where it previously failed to load entirely. Network isolation still requires a newer kernel.

Bug Fixes

On Linux, fixed all network connection telemetry being lost on kernels that cannot support network isolation; connection tracking now loads independently of isolation.
On Linux, fixed the DNS tracker staying on packet capture for the life of the sensor when it started before kernel acquisition was ready, leaving DNS events without a process ID on hosts where the kernel could provide one.
On Linux, fixed the process tracker staying on its netlink fallback under the same conditions, which could leave short-lived processes without a path or command line.
On Linux, hardened kernel DNS collection against packets whose declared payload length exceeds what they carry; such packets could corrupt the sensor's buffer and caused the DNS events behind them to be discarded.
On Linux, fixed sensor diagnostics reporting every kernel telemetry subprogram as inactive when the reporting component had simply not yet queried the kernel; the status is now omitted until it is known.
Fixed a possible deadlock when the sensor is stopped by a signal on Linux and macOS.

Improvements

On Linux, sensor diagnostics now report whether DNS events are being attributed to a process.

Endpoint Agent 5.3.6

Fri, 14 Aug 2026 00:00:00 GMT

New Features

Linux hosts that cannot provide a cgroup2 mount — unprivileged containers, read-only root filesystems, kernels built without cgroup BPF support — now keep kernel-level file, process, socket and network telemetry instead of losing all of it.

Bug Fixes

Fixed the sensor silently discarding queued events when its outbound queue filled up; discarded events are now counted and reported.
The outbound event queue is now bounded by memory size as well as by event count, so a few very large events can no longer displace thousands of small ones.
Fixed every kernel-sourced DNS event on Linux reporting process ID 0 and being held for 10 seconds before delivery.
Fixed Linux network isolation being reported as available on hosts where the sensor could not exempt its own connection, where isolating the host would have cut off the connection needed to un-isolate it.
Fixed the sensor aborting under Wine while collecting Windows Event Log events; an incomplete Event Log bookmark implementation is now detected at the point of use and log resumption is disabled cleanly.
macOS file-access monitoring now matches file extensions case-insensitively, so a rule for .docx also matches Report.DOCX. Linux continues to match exactly.
Removing an adhoc exfil rule now returns a receipt reporting whether the rule was found and removed, matching the behavior of adding one.

Improvements

Sensor diagnostics now report how many events the outbound queue has discarded, their estimated size, and the current queue depth against its limits.
Sensor diagnostics now report which Linux kernel telemetry subprograms are active, so a partial kernel acquisition is visible rather than appearing healthy.
On Linux hosts without kernel DNS support, DNS collection now falls back to packet capture, and packet captures are opened only when that fallback is actually in use instead of on every Linux sensor.
The sensor now warns when file-access monitoring is enabled with no file patterns configured, instead of appearing healthy while unable to report anything.

Endpoint Agent 5.3.5

Tue, 11 Aug 2026 00:00:00 GMT

New Features

Linux process events now identify the container a process belongs to, including its Kubernetes pod; the fields are absent for ordinary host processes.
New Windows script visibility through the Antimalware Scan Interface: scripts and .NET assemblies are reported as the host application submits them for scanning, already deobfuscated. Enabled from the cloud.
YARA memory detections now report the address of the match, so a detection points at the exact location in the target process.
YARA rules can now use the macho module to inspect Mach-O images.

Bug Fixes

Fixed cloud-driven sensor upgrades never taking effect on macOS. The new binary is now put in place atomically before the service is stopped, on both macOS and Linux.
Fixed the sensor sitting connected but idle for up to 10 minutes after its cloud connection was replaced, delaying collectors and telemetry; it now re-syncs immediately.
Fixed the sensor hanging indefinitely when a configured proxy accepts the connection but never answers the CONNECT request; the attempt is now bounded and retried.
Proxy replies split across packets, sent with LF-only headers, or answering with a 2xx status other than 200 are now handled correctly.
Fixed the sensor's log file being created world-writable on installed Linux sensors.
Uninstalling on Linux now removes the kernel acquisition mount point it used to leave behind, and macOS uninstall now deregisters its installer receipt.
Fixed the arm64 Debian package being refused by dpkg; it is now published as limacharlie_<version>_arm64.deb.
Payload downloads and artifact uploads are now strictly compliant HTTP, so filtering proxies and SSL inspection agents no longer drop them as malformed.
Fixed artifact uploads reporting success while delivering no data when a network device answered with a redirect.
Fixed certificate verification failures for payload downloads, artifact uploads and sensor upgrades on hosts with enterprise TLS inspection roots; verification now uses the operating system trust store alongside the built-in certificates.
Fixed the sensor deadlocking while listing process handles when Windows stopped answering a handle name query.
Fixed process hollowing detection rescanning every module in full instead of skipping the parts already matched on disk.
Fixed stateful detection tracking comparing only part of its key, which could route events to the wrong tracking group.
Fixed the sensor aborting under Wine when probing the Windows Event Log bookmark API.
Fixed a potential out-of-bounds read when matching short YARA rule namespaces.
Corrected swapped country and organization labels in the sensor's certificate issuer output.

Improvements

Payload download and artifact upload failures now report a readable description in the command receipt and in the local log, instead of a bare numeric code.
Transfer failures that previously all reported error 0 now report distinct codes: a sensor that has not yet received its artifact configuration, and a connection closed without a response.
Payload downloads and artifact uploads now use a full HTTP client, adding chunked response support, correct response framing and enforced timeouts.
The Linux x86_64 and i386 sensor now requires glibc 2.12 instead of 2.17, so it installs on older distributions; the optional eBPF module still requires 2.14.
A configuration update is no longer held up by an in-progress payload download.
The payload download size limit now applies to the whole transfer rather than to each resumed request.

Endpoint Agent 5.3.4

Tue, 28 Jul 2026 00:00:00 GMT

New Features

The registry listing command can now recursively list sub-keys down to an optional maximum depth, reporting fully-qualified key paths; oversized results are returned as partial replies flagged for follow-up.

Bug Fixes

Fixed corrupted process events from macOS kernel acquisition: invalid timestamps, missing file paths and command lines, and spurious phantom process records.
Fixed file transfers and the sensor's cloud connection aborting when a TLS 1.3 server sends a post-handshake session ticket, common behind SSL-inspection proxies.
Fixed repeated payload put commands failing on Windows: moving a file into place now overwrites an existing destination, matching other platforms.
Fixed payload downloads and log/artifact uploads failing when certificate verification is explicitly disabled.
Uninstalling the Windows MSI now fully removes the sensor's identity and data, so a later reinstall enrolls as a fresh sensor.
Fixed a rare crash caused by concurrent use of the sensor's random number generator, seen most often on macOS under heavy file activity.
Fixed a crash on sensor shutdown after a partially failed startup.
Fixed a potential crash when reading executable paths from the Windows registry under low-memory conditions.
Fixed assorted small latent bugs across the sensor uncovered by expanded static analysis.

Improvements

Windows Event Log collection now resumes from where it left off after a sensor restart, recovering events logged while the sensor was not running.
Sensor upgrade and uninstall operations now write warnings and errors to a dedicated log file in the sensor data directory.
Listing endpoint protection exclusions now reports an error code on failure, distinguishing a failed query from a host with no exclusions.
Windows WMI query failures now report a dedicated WMI error code instead of a generic failure, for example when Defender is disabled by policy.

Endpoint Agent 5.3.3

Tue, 14 Jul 2026 00:00:00 GMT

New Features

The sensor service can now be upgraded or uninstalled through cloud tasking.
Upgrade and uninstall commands reply with their result, including the OS error code on failure.
Sensor upgrades can be pinned to a specific version.
Sensor connections now report a unique per-boot identifier to the cloud.
Sensor connections now report the main network interface's MAC address.
Windows endpoint protection status now falls back to Security Center antivirus data when the Defender query fails.

Bug Fixes

Sensors that connect but receive no data from the cloud now retry with a fresh TLS handshake after 30 seconds.
Fixed connection failures under pinned-certificate trust: TLS hostname verification now applies only to public CA trust.
Fixed a TLS 1.2 handshake failure with servers using certain RSA-PSS signature schemes.
Fixed macOS notarization of the sensor binary.
Fixed a thread-synchronization race on Linux and macOS that could destabilize the sensor.
Fixed a small memory leak when kernel acquisition shuts down on macOS.
Fixed incorrect formatting in several sensor debug log messages.
Fixed assorted small bugs across the sensor on Linux and Windows.

Improvements

Updated the embedded TLS library (mbedtls) to 4.1.1.

Endpoint Agent 5.3.2

Mon, 06 Jul 2026 00:00:00 GMT

Bug Fixes

Fixed connection failures under pinned-certificate trust: TLS hostname verification now applies only to public CA trust.
Fixed a TLS 1.2 handshake failure with servers using certain RSA-PSS signature schemes.

Endpoint Agent 5.3.1

Thu, 02 Jul 2026 00:00:00 GMT

New Features

TLS 1.3 is now supported for the sensor's connection to the LimaCharlie cloud, with automatic fallback to TLS 1.2.
Shell commands can now be run as a specific user instead of always running with the sensor's own privileges.
USB Data Loss Prevention is now configuration-driven, so the enforcement mode and allowed-device list persist across restarts and can be managed centrally from the cloud.

Bug Fixes

Improved the reliability of running shell commands: fixed lost error output, incorrect exit codes, and commands being cut short on hosts whose clock jumps.
Endpoint protection status now reports specific errors when a query fails, instead of a single generic failure.
Fixed several memory-safety issues and memory leaks across the sensor, including at shutdown and on Windows.

Improvements

Linux kernel component failures are now easier to diagnose, with more detail reported in its status.

Endpoint Agent 5.3.0

Fri, 05 Jun 2026 00:00:00 GMT

New Features

New reg_get command fetches a single named Windows registry value by key and value name, for values too large or keys too crowded to retrieve with reg_list.
macOS installation is now a single guided window with a three-step checklist — system extension, network content filter, Full Disk Access — replacing the previous sequence of seven separate prompts.

Bug Fixes

Fixed macOS file-creation events reporting the parent directory instead of the new file's path, which stopped exfil watch rules from matching specific files.
Fixed a leak of registry key handles when listing Windows registry keys.

Improvements

File hashing is faster and allocates far less memory, lowering sensor overhead on hosts with heavy file activity.

Endpoint Agent 5.2.6

Sat, 30 May 2026 00:00:00 GMT

Bug Fixes

Fixed very large artifact uploads never completing: each part is now retried up to ten times with backoff, so a brief network interruption no longer restarts the transfer from the beginning.
Fixed uploads of locked files larger than 4 GB on Windows looping indefinitely over the first 4 GB.
The sensor now shuts down promptly while an upload is retrying, instead of waiting out its backoff.

Endpoint Agent 5.1.0

Thu, 02 Apr 2026 00:00:00 GMT

New Features

The os_drivers command now works on Linux, listing the host's loaded kernel modules.
The sensor health check now downloads and verifies the latest health-check binary from the cloud, so diagnostics stay current without upgrading the sensor.

Bug Fixes

Fixed macOS and Windows sensors staying on a dead connection for hours after a network disruption; keepalive behavior is now consistent across all platforms and connections recover promptly.
Fixed occasional missing line breaks in the sensor's local log file.

Improvements

The sensor health check now reports details of the installed sensor binary on disk.
Sensor debug data now includes the sensor service version.
Sensor service details are now reported to the cloud on every sync, instead of only when debug data is requested.
Linux and macOS sensor binaries are smaller.

Endpoint Agent 4.33.26

Sun, 08 Feb 2026 00:00:00 GMT

Feature: Windows ARM64 support
Fix cloud initialization issue on start and reboots
Fix an eBPF umount issue on Linux whenever LVM is used

Endpoint Agent

Fri, 24 Oct 2025 00:00:00 GMT

Stable: 4.33.10.5

Fix an issue with the epp_list_exclusions command not showing all exclusions

Latest: 4.33.19

Fix an issue with the epp_list_exclusions command not showing all exclusions
Change the compression algorithm for Debian installer packages from xz to gzip for better compatibility with older distributions

Endpoint Agent

Fri, 17 Oct 2025 00:00:00 GMT

New stable release 4.33.10.4 - fixed memory leak in file type tracker, upgrade recommended.

New release 4.33.18:

Number of fixes including:

A memory leak in the file type tracker
Potential crashes in cloud task processing and log tracker
Version reporting fixes on Windows 11, Linux, and macOS
Certificate updates to avoid solely relying on the platform keychain
Update the size of the file tracking buffer to avoid missing events on Linux

Endpoint Agent v4.33.15

Fri, 12 Sep 2025 00:00:00 GMT

macOS system extension: fixes for potential install and upgrade issues, improved logging for troubleshooting
Fixes a macOS install issue when using the package installer (.pkg)

Endpoint Agent 4.33.14

Thu, 28 Aug 2025 00:00:00 GMT

Reduce CPU usage of the OS tracker. The component is used for: new system service notifications, new driver notifications, and new autoruns/bootstrap notifications.

Endpoint Agent 4.33.13 and 4.33.10.3

Fri, 08 Aug 2025 00:00:00 GMT

Fix a Windows 2016 compatibility issue in the kernel driver for both lc:stable (4.33.10.3) and lc:latest (4.33.13) versions.

Endpoint Agent 4.33.11

Fri, 18 Jul 2025 00:00:00 GMT

Bug Fixes:

Resolved event loss on high-traffic Windows systems
Fixed kernel upgrade failures that could occur during system updates
Addressed code signing compatibility issues on macOS

Breaking Changes:

Console logging is now opt-in via -v or --verbose flags. The previous -v flag for displaying installer version has been changed to -V. This improves default output cleanliness while maintaining debugging capabilities.

New stable version is now 4.33.10.

Endpoint Agent 4.33.9

Fri, 27 Jun 2025 00:00:00 GMT

Important fixes for Windows 7 and Windows 8 support.

Endpoint Agent 4.33.8

Fri, 30 May 2025 00:00:00 GMT

Fix a potential deadlock on upgrade in the HBS component
Fix a reverse logic issue processing the LC_DISABLE_REVERSE_DNS_HOSTNAME environment variable. Accepted values: 1, true, 0, false (case insensitive)

Endpoint Agent 4.33.7

Thu, 22 May 2025 00:00:00 GMT

Linux:

Fix some Linux GLIBC compatibility issues. The minimum GLIBC supported version is now 2.17 (released 2012) for all 3 supported architectures (x86, x86_64, and ARM64)
Fix the Linux Alpine / musl libc binaries

macOS:

Standalone installer is now a universal binary (FAT) to prevent users from installing on the wrong architecture
Fix an issue where the host isolation command wouldn't terminate existing connections

Windows:

Added an environment variable (LC_LOCAL_CACHE_ONLY_REVOCATION_CHECK) to prevent the Windows WinTrust code signing library from updating its revocation cache from the internet. The default and recommended setting is to let WinTrust update its cache, but the sensor may connect to content delivery networks (CDNs) on port 80 to do so.

General:

The sensor troubleshooting tool (rphcp -H) was missing in the .deb, .msi, and .pkg installers

Endpoint Agent 4.33.6

Fri, 18 Apr 2025 00:00:00 GMT

Allow the sensor to drop the VDI file (delayed start) during the installation procedure via -t
Added a sensor troubleshooting utility: a standalone command and a command line option for the sensor (-H) to help diagnose common misconfigurations and connectivity problems

Endpoint Agent 4.33.5

Fri, 11 Apr 2025 00:00:00 GMT

Performance improvements for macOS
Infrastructure work to support Endpoint Protection Platforms (EPP), and added support for Microsoft Windows Defender

Note of Change

LC Detection Events are now immutable. One can no longer remove past events or modify them in any way, as detection events are a factual historic record and it's prudent to keep them as such.

Endpoint Agent v4.33.4

Fri, 28 Mar 2025 00:00:00 GMT

Fix missing pipe event for Windows
Fix the kernel acquisition module for Linux ARM64 builds

EDR Agent v4.33.2

Thu, 06 Mar 2025 00:00:00 GMT

Fixed a path expansion issue that would cause the cleanup command on Windows to leave configuration files after the uninstallation procedure.

EDR Endpoint Agent v4.33.1

Fri, 21 Feb 2025 00:00:00 GMT

Fix various directory and file permissions on macOS
Added a status file to help troubleshooting. The status file contains the sensor ID, organization ID, version, and the agent's service uptime.

Status file locations:

Platform Path

Linux /opt/limacharlie/hcp_hbs_status.json

macOS /Library/Application Support/limacharlie/hcp_hbs_status.json

Windows C:\ProgramData\limacharlie\hcp_hbs_status.json
Fix a missing package name for Microsoft Edge Update on Windows
Fix a pattern matching issue that was affecting file integrity notifications
Added the LC_DISABLE_REVERSE_DNS_HOSTNAME environment variable for customers wanting to use the local hostname instead of resolving it

Platform	Path
Linux	`/opt/limacharlie/hcp_hbs_status.json`
macOS	`/Library/Application Support/limacharlie/hcp_hbs_status.json`
Windows	`C:\ProgramData\limacharlie\hcp_hbs_status.json`

EDR Sensor v4.31.1

Sat, 19 Oct 2024 00:00:00 GMT

Network connection stability enhancements on all platforms.

The enhancements are in both the cloud-triggered upgrade version of the sensor AND in the on-disk installation, but there is no requirement to deploy both simultaneously.