CVE-2026-123370: tmatens compose-lint · Off-by-one Error
Affects tmatens compose-lintSource CVE Database V5
Not known to be exploited · CVSS 5.1 Medium : upgrade to 0.18.0 when convenient.
Data as of 9 Nov 2026, 17:49 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 5.1 |
|---|
- Patch
- Available – fixed in 0.18.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade tmatens compose-lint to 0.18.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| tmatenscompose-lint | Affected
| Fixed in
|
AI-suggested
Upgrade compose-lint to version 0.18.0 or later, where this off-by-one error in the YAML parser is fixed. Users should avoid relying on fix --apply in affected versions (>=0.9.0 <0.18.0) to prevent unintended deletions. No other mitigation is indicated by the vendor.
Description
compose-lint versions from 0.9.0 up to but not including 0.18.0 contain an off-by-one error in their YAML parser related to handling certain line break characters. This flaw causes the fix --apply command to incorrectly shift edits and delete lines following the targeted line, potentially removing unselected network or security settings. The Compose file remains valid and post-edit checks pass, making the unintended deletion difficult to detect. The issue is resolved in version 0.18.0.
References
- github.com/tmatens/compose-lint/security/advisories/GHSA-65v8-q222-64xx (opens in a new tab)
- github.com/tmatens/compose-lint/pull/547 (opens in a new tab)
- github.com/tmatens/compose-lint/pull/549 (opens in a new tab)
- github.com/tmatens/compose-lint/commit/c9d453a6a69c076788fe1db05cb54684a616d1de (opens in a new tab)
- github.com/tmatens/compose-lint/commit/cbbf886d91347dea9c51b584eb50088e70007d0d (opens in a new tab)
- github.com/tmatens/compose-lint/releases/tag/v0.18.0 (opens in a new tab)