CVE-2026-71267
CRITICALCVE-2026-71267 is a critical-severity (CVSS 9.8) CWE-121 vulnerability. O3 Security confirms whether CVE-2026-71267 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
microtar's mtar_write_file_header() and mtar_write_dir_header() functions (src/microtar.c) copy a caller-supplied entry name into the 100-byte `name` field of a stack-allocated mtar_header_t…
Description
microtar's mtar_write_file_header() and mtar_write_dir_header() functions (src/microtar.c) copy a caller-supplied entry name into the 100-byte name field of a stack-allocated mtar_header_t via strcpy(h.name, name), with no check that strlen(name) is less than 100 before the copy. Any application that calls these functions with an externally-influenced filename longer than 99 characters (e.g. when archiving user-supplied or attacker-controlled filenames) triggers a stack buffer overflow.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-71267 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-71267 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-71267. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-71267 in your dependencies?
O3 detects CVE-2026-71267 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.