CVE-2026-23455

Aliases:UBUNTU-CVE-2026-23455DEBIAN-CVE-2026-23455
Advisory lineage Upstream: 0 Downstream: 37
Modified
Published: 03 Apr 2026, 15:15
Last modified:08 Sept 2026, 08:46

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.1 CRITICAL
v3.1 (cve.org)
EPSS Score
1.34% LOW
1% probability +0.82%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

03 Apr 2026, 15:15
Published
Vulnerability first disclosed
08 Sept 2026, 08:46
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v4.0•HIGH•Score: 8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
  • v3.1•CRITICAL•Score: 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS Trends

Current EPSS score: 1.34%• Percentile: 70%

Techniques & Countermeasures

  • CWE-125•Out-of-bounds Read

    The product reads data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • debian•linux

    < 5.10.257-1 | < 6.1.170-1 | < 6.12.85-1 | < 6.19.10-1

  • debian•linux-6.1

    < 6.1.170-1~deb11u1

  • ubuntu•linux

    all | < 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

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 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

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1111.118~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1161.172~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.14

    all

  • ubuntu•linux-aws-6.17

    < 6.17.0-1019.19~24.04.1

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1060.63~22.04.1

  • ubuntu•linux-aws-fips

    < 4.15.0-2132.138 | all | < 5.4.0-1161.172+fips1 | < 5.15.0-1111.118+fips1 | < 6.8.0-1060.63+fips1

  • ubuntu•linux-aws-hwe

    all | < 4.15.0-1194.207~16.04.1

  • ubuntu•linux-azure

    all | < 4.15.0-1205.220~14.04.1 | < 4.15.0-1204.219~16.04.1 | all | < 5.4.0-1166.172 | < 5.15.0-1116.125 | < 6.8.0-1063.71 | all

  • ubuntu•linux-azure-4.15

    < 4.15.0-1204.219

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1116.125~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1166.172~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    all

  • ubuntu•linux-azure-6.14

    all

  • ubuntu•linux-azure-6.17

    < 6.17.0-1021.21~24.04.1

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1063.71~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | all | < 6.8.0-1062.69 | all

  • ubuntu•linux-azure-fde-5.15

    < 5.15.0-1116.125~20.04.1

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.14

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fde-6.8

    < 6.8.0-1062.69~22.04.1

  • ubuntu•linux-azure-fips

    < 4.15.0-2112.118 | all | < 5.4.0-1166.172+fips1 | < 5.15.0-1116.125+fips1 | < 6.8.0-1062.69+fips1

  • ubuntu•linux-azure-nvidia

    all

  • ubuntu•linux-azure-nvidia-6.14

    all

  • ubuntu•linux-bluefield

    all | < 5.4.0-1120.127 | < 5.15.0-1095.97 | < 6.8.0-1026.30

  • ubuntu•linux-fips

    < 4.4.0-1126.133 | all | < 4.15.0-1149.161 | < 5.4.0-1135.145 | < 5.15.0-185.195+fips1 | < 6.8.0-134.134+fips1

  • ubuntu•linux-gcp

    all | < 4.15.0-1187.204~16.04.1 | all | < 5.4.0-1164.173 | < 5.15.0-1111.121 | < 6.8.0-1063.69 | < 6.17.0-1020.22

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1187.204

  • ubuntu•linux-gcp-5.11

    all

Showing first 50 affected entries in server-rendered view.

References (52)