CVE-2026-43499

Aliases:RHSA-2026:41920UBUNTU-CVE-2026-43499DEBIAN-CVE-2026-43499
Advisory lineage Upstream: 0 Downstream: 71
Modified
Published: 21 May 2026, 12:17
Last modified:08 Sept 2026, 08:48

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.79% LOW
1% probability +0.06%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

21 May 2026, 12:17
Published
Vulnerability first disclosed
08 Sept 2026, 08:48
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]

CVSS Metrics

  • v4.0•HIGH•Score: 8.5CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.79%• Percentile: 55%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • debian•linux

    < 5.10.262-1 | < 6.1.176-1 | < 6.12.86-1 | < 7.0.4-1

  • debian•linux-6.1

    < 6.1.176-1~deb11u1

  • ubuntu•linux

    all | < 3.13.0-215.266 | < 4.4.0-284.318 | < 4.15.0-254.266 | < 5.4.0-234.254 | < 5.15.0-187.197 | < 6.8.0-136.136 | all | < 7.0.0-27.27

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 4.4.0-1157.163 | < 4.4.0-1195.210 | < 4.15.0-1195.208 | < 5.4.0-1162.173 | < 5.15.0-1113.120 | < 6.8.0-1061.64 | all | < 7.0.0-1008.8

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    all | < 5.15.0-1114.121~20.04.1

  • 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

    < 4.15.0-2133.139 | all | < 5.4.0-1163.174+fips1 | < 5.15.0-1113.120+fips1 | < 6.8.0-1061.64+fips1

  • ubuntu•linux-aws-hwe

    all | < 4.15.0-1195.208~16.04.1

  • ubuntu•linux-azure

    all | < 4.15.0-1205.220~14.04.1 | < 4.15.0-1205.220~16.04.1 | all | < 5.4.0-1167.173 | < 5.15.0-1118.127 | < 6.8.0-1063.71 | all | < 7.0.0-1010.10

  • ubuntu•linux-azure-4.15

    < 4.15.0-1205.220

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    all | < 5.15.0-1119.128~20.04.1

  • 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

    < 6.17.0-1022.22

  • 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 | < 5.15.0-1118.127 | < 6.8.0-1062.69 | all | < 7.0.0-1009.9

  • ubuntu•linux-azure-fde-5.15

    all | < 5.15.0-1118.127~20.04.1

  • 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

    < 4.15.0-2113.119 | all | < 5.4.0-1167.173+fips1 | < 5.15.0-1118.127+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 | < 5.15.0-1097.99 | < 6.8.0-1028.33

  • ubuntu•linux-fips

    < 4.4.0-1127.134 | all | < 4.15.0-1150.162 | < 5.4.0-1136.146 | < 5.15.0-190.200+fips1 | < 6.8.0-136.136+fips2

  • ubuntu•linux-gcp

    all | all | < 4.15.0-1188.205~16.04.1 | all | < 5.4.0-1165.174 | < 5.15.0-1114.124 | < 6.8.0-1064.72 | all | < 7.0.0-1007.7

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1188.205

  • ubuntu•linux-gcp-5.11

    all

Showing first 50 affected entries in server-rendered view.

References (66)