7.8

CVE-2026-23274: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels

Modified
AliasesUBUNTU-CVE-2026-23274DEBIAN-CVE-2026-23274
Published 20-03-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-23274 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · 0.00 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 41 · Related 45
OPENSUSE-SU-2026:20572-1SUSE-SU-2026:1342-1SUSE-SU-2026:1557-1SUSE-SU-2026:1563-1SUSE-SU-2026:1573-1SUSE-SU-2026:1574-1

Timeline

  1. 20-03-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.18% 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: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu144 products
  • linux< 5.15.0-179.189 | < 6.8.0-117.117 | < 6.17.0-29.29
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1108.115 | < 6.8.0-1055.58 | < 6.17.0-1015.15
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 68983a354a655c35d3fb204489d383a2a051fda7, < 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa44 | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < 144f88054ba0180467356f40895bd660b5dceeec | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < 28c7cfaf0c0ab17cbd7754092116fd1af45271f9 | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < 54080355999381fed4a26129579a5765bab87491 | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < 5e7ece24c5cb75a60402aad4d803c7898ea40aa9 | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < f5ef97c13165542480a6ffdbe6f09f40bbb7cbf1 | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < f228b9ae2a7e84d1153616d8e71c4236cb1f1309 | ≥ 68983a354a655c35d3fb204489d383a2a051fda7, < 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf | 5.7
  • linux_kernel≥ 5.7, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.167 | ≥ 6.2, < 6.6.130 | ≥ 6.7, < 6.12.78 | ≥ 6.13, < 6.18.19 | ≥ 6.19, < 6.19.9 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.10-1

3 vendors · 147 products

References

40 links
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