CVE-2026-23455
No exploitation reported by the sources we read.
- Published2026-04-03
- Fixed in6.19.10 · 6.18.20 · 6.12.78 · 6.6.130 · 6.1.167 · 5.15.203
- WeaknessCWE-125
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() In DecodeQ931(), the UserUserIE code path reads a 16-bit length from the packet, then decrements it by 1 to skip the protocol discriminator byte before passing it to DecodeH323_UserInformation(). If the encoded length is 0, the decrement wraps to -1, which is then passed as a large value to the decoder, leading to an out-of-bounds read. Add a check to ensure len is positive after the decrement.
Timeline
dates in UTC- 2026-04-0316:16CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-23455?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-23455?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 6.19 | ≥ 6.19, < 6.19.10 | 6.19.10 | NVD |
| 6.x | ≥ 6.13, < 6.18.20 | 6.18.20 | NVD |
| 6.x | ≥ 6.7, < 6.12.78 | 6.12.78 | NVD |
| 6.x | ≥ 6.2, < 6.6.130 | 6.6.130 | NVD |
| 6.1 | ≥ 5.16, < 6.1.167 | 6.1.167 | NVD |
| 5.x | ≥ 5.11, < 5.15.203 | 5.15.203 | NVD |
| 5.10 | ≥ 2.6.17, < 5.10.253 | 5.10.253 | NVD |
| 7.0 | = 7.0 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Packages
- kernelAlmaLinux:10all versions · fixed in 6.12.0-211.18.1.el10_2and 74 other packages
- kernelAlmaLinux:9all versions · fixed in 5.14.0-687.12.1.el9_8and 73 other packages
- kernelAlmaLinux:8all versions · fixed in 4.18.0-553.126.1.el8_10and 24 other packages
- kernel-rtAlmaLinux:8all versions · fixed in 4.18.0-553.126.1.rt7.467.el8_10and 9 other packages
Fix
- Update Linux linux kernel to 6.19.10 · 6.18.20 · 6.12.78 · 6.6.130 · 6.1.167 · 5.15.203 · 5.10.253
Advisories and patches
- git.kernel.orgPatch
- git.kernel.orgPatch
- git.kernel.orgPatch
- git.kernel.orgPatch
- git.kernel.orgPatch
- git.kernel.orgPatch
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- Published
- 2026-04-03
- Last Modified
- 2026-10-19
- NVD status
- Modified
Frequently asked questions
What is CVE-2026-23455?
Is CVE-2026-23455 actively exploited?
What is the CVSS score for CVE-2026-23455?
Running Linux kernel? Hear about its next vulnerability
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.