CVE-2025-39802

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: arm/poly1305: Fix register corruption in no-SIMD contexts Restore the SIMD usability check that was removed by commit 773426f4771b ("crypto: arm/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/52c3e242f4d0043186b70d65460ba1767f27494a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/87bdfba903be7084cb3ee04032b14a81181fe413
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/52c3e242f4d0043186b70d65460ba1767f27494a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/87bdfba903be7084cb3ee04032b14a81181fe413
    Patch