CVE Catalog

CVE-2025-39804

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.23%

14th percentile - higher than 14% of all known CVEs

Summary

In the Linux kernel, the ARM64 Poly1305 implementation lacked a SIMD usability check, which could corrupt other tasks' registers or compute incorrect MACs. The fix restores this check.

Risk Assessment

The risk involves potential data corruption of other processes or incorrect message authentication, leading to system integrity issues.

Recommendation

Immediately update the Linux kernel to a version containing this fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: lib/crypto: arm64/poly1305: Fix register corruption in no-SIMD contexts Restore the SIMD usability check that was removed by commit a59e5468a921 ("crypto: arm64/poly1305 - Add block-only interface"). This safety check is cheap and is well worth eliminating a footgun. While the Poly1305 functions should not be called when SIMD registers are unusable, if they are anyway, they should just do the right thing instead of corrupting random tasks' registers and/or computing incorrect MACs. Fixing this is also needed for poly1305_kunit to pass. Just use may_use_simd() instead of the original crypto_simd_usable(), since poly1305_kunit won't rely on crypto_simd_disabled_for_test.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS