# CVE-2026-129119: C-Kermit 6.0.192 before 11.1.515 File Collision Protection Bypass via RESEND

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

C-Kermit from 6.0.192 before 11.1.515 contains a file collision protection bypass that allows malicious senders to append data to existing files by marking transfers as RESEND. The gattr() function in ckcfn3.c clears the REJECT discard flag and switches to APPEND without a RECEIVE CONFIRM prompt, letting attackers modify files such as shell startup files.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/OpenKermit/ckermit/commit/bbf9923e3e2e04ac3da713998cb15e786e26fdf1

## Affected products and versions

- OpenKermit / C-Kermit (OpenKermit/ckermit): ≥ 6.0.192; < 11.1.515 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.1 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N; source: CNA: VulnCheck

- CVSS 4.0: 7.1 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-863

## Exploit evidence

- exploit: https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj (ADP: CISA-ADP)

## References

- https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj (CNA: VulnCheck; vendor-advisory)

- https://github.com/OpenKermit/ckermit/commit/bbf9923e3e2e04ac3da713998cb15e786e26fdf1 (CNA: VulnCheck; patch)

- https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515 (CNA: VulnCheck; release-notes)

- https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcfn3.c#L1798-L1800 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/c-kermit-6.0.192-before-11.1.515-file-collision-protection-bypass-via-resend (CNA: VulnCheck; third-party-advisory)

- https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj (ADP: CISA-ADP; exploit)

- https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcfn3.c#L1798-L1800 (disclosure@vulncheck.com)

- https://github.com/OpenKermit/ckermit/commit/bbf9923e3e2e04ac3da713998cb15e786e26fdf1 (disclosure@vulncheck.com)

- https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515 (disclosure@vulncheck.com)

- https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/c-kermit-6.0.192-before-11.1.515-file-collision-protection-bypass-via-resend (disclosure@vulncheck.com)

- https://github.com/OpenKermit/ckermit/security/advisories/GHSA-vhrv-7jrq-95qj (134c704f-9b21-4f2e-91b3-4a467353bcc0)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-129119; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-129119; retrieved 2026-11-14; source updated 2026-11-13

Revision: 84dcdf3b0042e6663e80d00773cccfb0220cdd8fe186cd84e67db5097b679eda

Canonical: https://y2.dev/cve/CVE-2026-129119

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