5.5

CVE-2026-23405: linux

CVSS: 5.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-23405DEBIAN-CVE-2026-23405
Published 01-04-2026Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2026-23405 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.2% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.18%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 13 · Related 15
SUSE-SU-2026:21834-1SUSE-SU-2026:2195-1SUSE-SU-2026:2238-1USN-8098-10USN-8152-1USN-8163-1

Timeline

  1. 01-04-2026
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix: limit the number of levels of policy namespaces Currently the number of policy namespaces is not bounded relying on the user namespace limit. However policy namespaces aren't strictly tied to user namespaces and it is possible to create them and nest them arbitrarily deep which can be used to exhaust system resource. Hard cap policy namespaces to the same depth as user namespaces.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

0.00 pp

From 0.18% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.18%

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

No weakness data has been published for this record.

Affected systems

Ubuntu156 products
  • linuxAll versions (No fix recorded) | < 4.15.0-249.261 | < 5.4.0-227.247 | < 5.15.0-173.183 | < 6.8.0-106.106 | < 6.17.0-19.19
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 4.15.0-1191.204 | < 5.4.0-1156.166 | < 5.15.0-1103.110 | < 6.8.0-1050.53 | < 6.17.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < 6b396cc2f0365e684fc1d3547d18ef79fcee225d | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < 87d0cecc900e55d55fc4dbfb43ac93e269c7a5b3 | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < b1226e37eb3754d389721c135db6107db94c7a72 | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < 3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < 853ce31ca72097d23991a06876a2ccb5cb64b603 | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < d42b2b6bb77ca40ee34ab74ad79305840b5f315d | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < 7b6495ead2c611647f6b11441a852324e3eb8616 | ≥ c88d4c7b049e87998ac0a9f455aa545cc895ef92, < 306039414932c80f8420695a24d4fe10c84ccfb2 | 2.6.36
  • linux_kernel≥ 2.6.36.1, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.169 | ≥ 6.2, < 6.6.130 | ≥ 6.7, < 6.12.77 | ≥ 6.13, < 6.18.18 | ≥ 6.19, < 6.19.8 | 2.6.36 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
Debian1 product
  • linux< 6.1.164-1 | < 6.12.74-2 | < 6.19.6-2

3 vendors · 159 products

References

28 links
Show all 28 references