CVE-2026-46193

MEDIUM EPSS 2.8%
Published May 28, 20261mo ago · Modified Jun 19, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published May 28, 2026 1mo ago
Last Modified Jun 19, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: ah: account for ESN high bits in async callbacks AH allocates its temporary auth/ICV layout differently when ESN is enabled: the async ahash setup appends a 4-byte seqhi slot before the ICV or auth_data area, but the async completion callbacks still reconstruct the temporary layout as if seqhi were absent. With an async AH implementation selected, that makes AH copy or compare the wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH with ESN and forced async hmac(sha1), ping fails with 100% packet loss, and the callback logs show the pre-fix drift: ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24 ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36 Reconstruct the callback-side layout the same way the setup path built it by skipping the ESN seqhi slot before locating the saved auth_data or ICV. Per RFC 4302, the ESN high-order 32 bits participate in the AH ICV computation, so the async callbacks must account for the seqhi slot. Post-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows the corrected offset (ah4 output_done: esn=1 err=0 icv_off=24 expected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o build clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the change has not been tested against a real async hardware AH engine.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
2.8% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 6

VendorProductVersionRange
linuxlinux_kernel*≥3.15  –  <6.6.140
linuxlinux_kernel*≥6.7  –  <6.12.88
linuxlinux_kernel*≥6.13  –  <6.18.30
linuxlinux_kernel*≥6.19  –  <7.0.7
linuxlinux_kernel7.1any
linuxlinux_kernel7.1any

References 7

  • git.kernel.org https://git.kernel.org/stable/c/0555d4f526232b3c9e3afbcd490c0c0793aefec6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/1dae77078ceb4bab833f7a4935f05c5b8c97b9ba
  • git.kernel.org https://git.kernel.org/stable/c/2ffaa7a94f9a4d22724364a1821735a0231d9f8d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/729899a2aa8bda7844be0cdcd3b470f11b912eda
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7db99a09b3bc87268287bc7ab5f2e7f382b5ad87
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ec406c26c97594124e79d14516b729a8d5dced62
  • git.kernel.org https://git.kernel.org/stable/c/ec54093e6a8f87e800bb6aa15eb7fc1e33faa524
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0555d4f526232b3c9e3afbcd490c0c0793aefec6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2ffaa7a94f9a4d22724364a1821735a0231d9f8d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/729899a2aa8bda7844be0cdcd3b470f11b912eda
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7db99a09b3bc87268287bc7ab5f2e7f382b5ad87
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ec54093e6a8f87e800bb6aa15eb7fc1e33faa524
    Patch