9.8

CVE-2026-31414: netfilter: nf_conntrack_expect: use expect->helper

Modified
AliasesUBUNTU-CVE-2026-31414DEBIAN-CVE-2026-31414
Published 13-04-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-31414 is a critical (CVSS 9.8) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 46.6% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.8 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.56%
0%100%
Low · -0.20 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 53 · Related 50
LSN-0122-1MGASA-2026-0108MGASA-2026-0110OPENSUSE-SU-2026:21388-1SUSE-SU-2026:22433-1SUSE-SU-2026:22436-1

Timeline

  1. 13-04-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: use expect->helper Use expect->helper in ctnetlink and /proc to dump the helper name. Using nfct_help() without holding a reference to the master conntrack is unsafe. Use exp->master->helper in ctnetlink path if userspace does not provide an explicit helper when creating an expectation to retain the existing behaviour. The ctnetlink expectation path holds the reference on the master conntrack and nf_conntrack_expect lock and the nfnetlink glue path refers to the master ct that is attached to the skb.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.56%

Chance of exploitation in the next 30 days

Percentile

47%

Versus all other CVEs

30-day change

Decrease -0.20 pp

From 0.76% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu157 products
  • linux< 3.13.0-215.266 | < 4.4.0-284.318 | < 4.15.0-254.266 | < 5.4.0-234.254 | < 5.15.0-187.197 | < 6.8.0-136.136 | All versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1157.163 | < 4.4.0-1195.210 | < 4.15.0-1195.208 | < 5.4.0-1162.173 | < 5.15.0-1113.120 | < 6.8.0-1061.64 | All versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ ea781f197d6a835cbb93a0bf88ee1696296ed8aa, < 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781 | ≥ ea781f197d6a835cbb93a0bf88ee1696296ed8aa, < e7ccaa0a62a8ff2be5d521299ce79390c318d306 | ≥ ea781f197d6a835cbb93a0bf88ee1696296ed8aa, < 4bd1b3d839172724b33d8d02c5a4ff6a1c775417 | ≥ ea781f197d6a835cbb93a0bf88ee1696296ed8aa, < b53294bff19e56ada2f230ceb8b1ffde61cc3817 | ≥ ea781f197d6a835cbb93a0bf88ee1696296ed8aa, < 3dfd3f7712b5a800f2ba632179e9b738076a51f0 | ≥ ea781f197d6a835cbb93a0bf88ee1696296ed8aa, < f01794106042ee27e54af6fdf5b319a2fe3df94d | 2.6.30
  • linux_kernel≥ 2.6.30, < 6.1.168 | ≥ 6.2, < 6.6.134 | ≥ 6.7, < 6.12.81 | ≥ 6.13, < 6.18.22 | ≥ 6.19, < 6.19.12 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.12-1

3 vendors · 160 products

References

53 links
Show all 53 references