CVE-2026-52993

Aliases:UBUNTU-CVE-2026-52993DEBIAN-CVE-2026-52993
Advisory lineage Upstream: 0 Downstream: 55
Modified
Published: 24 Jun 2026, 16:29
Last modified:05 Aug 2026, 12:32

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (cve.org)
EPSS Score
0.37% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

24 Jun 2026, 16:29
Published
Vulnerability first disclosed
05 Aug 2026, 12:32
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: tipc: fix double-free in tipc_buf_append() tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the old one. In tipc_buf_append(), it was being called with a pointer to a local variable which was a copy of the caller's skb pointer. If the skb was reallocated and validation subsequently failed, the error handling path would free the original skb pointer, which had already been freed, leading to double-free. Fix this by checking if head now points to a newly allocated reassembled skb. If it does, reassign *headbuf for later freeing operations.

CVSS Metrics

  • v4.0•CRITICAL•Score: 9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.37%• Percentile: 31%

Techniques & Countermeasures

  • CWE-415•Double Free

    The product calls free() twice on the same memory address.

  • CWE-763•Release of Invalid Pointer or Reference

    The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

Affected Systems

  • debian•linux

    < 5.10.259-1 | < 6.1.176-1 | < 6.12.94-1 | < 7.0.10-1

  • debian•linux-6.1

    < 6.1.176-1~deb11u1

  • ubuntu•linux

    all | < 4.15.0-257.269 | < 5.4.0-234.254 | < 5.15.0-186.196 | < 6.8.0-136.136 | all | < 7.0.0-28.28

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 4.15.0-1196.209 | < 5.4.0-1162.173 | < 5.15.0-1112.119 | < 6.8.0-1061.64 | all | < 7.0.0-1009.9

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1112.119~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    all | < 5.4.0-1162.173~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.14

    all

  • ubuntu•linux-aws-6.17

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1061.64~22.04.1

  • ubuntu•linux-aws-fips

    < 4.15.0-2134.140 | all | < 5.4.0-1163.174+fips1 | < 5.15.0-1112.119+fips1 | < 6.8.0-1061.64+fips1

  • ubuntu•linux-aws-hwe

    all | < 4.15.0-1196.209~16.04.1

  • ubuntu•linux-azure

    all | < 4.15.0-1206.221~14.04.1 | < 4.15.0-1206.221~16.04.1 | all | < 5.4.0-1167.173 | < 5.15.0-1117.126 | < 6.8.0-1063.71 | all | < 7.0.0-1010.10

  • ubuntu•linux-azure-4.15

    all | < 4.15.0-1206.221

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1117.126~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    all | < 5.4.0-1167.173~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    all

  • ubuntu•linux-azure-6.14

    all

  • ubuntu•linux-azure-6.17

    all

  • 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-7.0

    all

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | < 5.15.0-1117.126 | < 6.8.0-1062.69 | all | < 7.0.0-1009.9

  • ubuntu•linux-azure-fde-5.15

    < 5.15.0-1117.126~20.04.2

  • 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

    < 4.15.0-2114.120 | all | < 5.4.0-1167.173+fips1 | < 5.15.0-1117.126+fips1 | < 6.8.0-1063.71+fips2

  • ubuntu•linux-azure-nvidia

    all

  • ubuntu•linux-azure-nvidia-6.14

    all

  • ubuntu•linux-bluefield

    all | all | < 5.4.0-1121.128 | < 5.15.0-1096.98 | < 6.8.0-1028.33

  • ubuntu•linux-fips

    < 4.15.0-1151.163 | all | < 5.4.0-1136.146 | < 5.15.0-186.196+fips1 | < 6.8.0-136.136+fips2

  • ubuntu•linux-gcp

    all | < 4.15.0-1189.206~16.04.1 | all | < 5.4.0-1165.174 | < 5.15.0-1112.122 | < 6.8.0-1064.72 | all | < 7.0.0-1008.8

  • ubuntu•linux-gcp-4.15

    all | < 4.15.0-1189.206

Showing first 50 affected entries in server-rendered view.

References (64)