CVE-2026-49421

CVE-2026-49421 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-273.

Key facts

Description

The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup. The flag was silently dropped, so path resolution was not actually restricted. A process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory. A caller relying on this flag for path containment may delete files outside the intended directory tree.

Frequently asked questions

What is CVE-2026-49421?
The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup. The flag was silently dropped, so path resolution was not actually restricted. A process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory. A caller relying on this flag for path containment may delete files outside the intended directory tree.
Is CVE-2026-49421 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-49421?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-49421 published?
CVE-2026-49421 was published on 2026-08-19.

References

Other CWE-273 vulnerabilities

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