9.8

CVE-2026-31637: linux

CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2026-31637DEBIAN-CVE-2026-31637
Published 24-04-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-31637 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.59% chance of exploitation in the next 30 days, higher than 47.2% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.59%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 26 · Related 38
LSN-0121-1MGASA-2026-0108MGASA-2026-0110USN-8492-1USN-8492-2USN-8492-3

Timeline

  1. 24-04-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: reject undecryptable rxkad response tickets rxkad_decrypt_ticket() decrypts the RXKAD response ticket and then parses the buffer as plaintext without checking whether crypto_skcipher_decrypt() succeeded. A malformed RESPONSE can therefore use a non-block-aligned ticket length, make the decrypt operation fail, and still drive the ticket parser with attacker-controlled bytes. Check the decrypt result and abort the connection with RXKADBADTICKET when ticket decryption fails.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.59%

Chance of exploitation in the next 30 days

Percentile

47%

Versus all other CVEs

30-day change

+0.08 pp

From 0.51% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.59%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu157 products
  • linux< 3.13.0-214.265 | < 4.4.0-283.317 | < 4.15.0-253.265 | < 5.4.0-233.253 | < 5.15.0-185.195 | < 6.8.0-134.134 | < 6.17.0-40.40
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1156.162 | < 4.4.0-1194.209 | < 4.15.0-1194.207 | < 5.4.0-1161.172 | < 5.15.0-1111.118 | < 6.8.0-1060.63 | < 6.17.0-1019.19
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < 252157d939d179b5d767cb860ff8fa7f8723b67a | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < a75b3b361dd481d942c5f259a82d59718a41092c | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < b3a808cd0790b5075aaa2bc3588edf02cd71d352 | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < 47073aab8a3a5a7b41c9bd37d2a3dcbeeccd6c8a | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < a149dcae23309df9de1c3b6b5d468610ef5ab7de | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < 22f6258e7b31dba9bf88dce4e3ee7f0f20072e60 | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < 58fcd1b156152613ba00a064a129fb69507ddd7d | ≥ 17926a79320afa9b95df6b977b40cca6d8713cea, < fe4447cd95623b1cfacc15f280aab73a6d7340b2 | 2.6.22
  • linux_kernel≥ 2.6.22.1, < 6.6.135 | ≥ 6.7, < 6.12.82 | ≥ 6.13, < 6.18.23 | ≥ 6.19, < 6.19.13 | 2.6.22 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
Debian1 product
  • linux< 6.1.176-1 | < 6.12.85-1 | < 6.19.13-1

3 vendors · 160 products

References

52 links
Show all 52 references