CVE-2025-39804

HIGH EPSS 3.2%
Published Sep 15, 20259mo ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
High
Find Similar
Published Sep 15, 2025 9mo ago
Last Modified Jun 17, 2026 2w ago

Description

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.

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
3.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 1

VendorProductVersionRange
linuxlinux_kernel*≥6.16  –  <6.16.4

References 2

  • git.kernel.org https://git.kernel.org/stable/c/eec76ea5a7213c48529a46eed1b343e5cee3aaab
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ef74efa598b7bbc5c24509f7f56af2806f81c339
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/eec76ea5a7213c48529a46eed1b343e5cee3aaab
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ef74efa598b7bbc5c24509f7f56af2806f81c339
    Patch