7.8

CVE-2026-74637: linux

CVSS: 7.8v3.1HighReceived
AliasesUBUNTU-CVE-2026-74637DEBIAN-CVE-2026-74637
Published 22-08-2026Last modified 16-10-2026
Open JSON

Vulnerability summary

CVE-2026-74637 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.13%
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 5 · Related 4
MGASA-2026-0506OPENSUSE-SU-2026:22091-1SUSE-SU-2026:4640-1SUSE-SU-2026:4706-1USN-8886-1

Timeline

  1. 22-08-2026
    PublishedVulnerability first disclosed.
  2. 16-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix group leader use-after-free after sibling detach perf_group_detach() handles leader and sibling detach differently. When the group leader is detached, all siblings are promoted to singleton events and their group_leader pointer is reset to themselves. When a sibling is detached, it is removed from the leader's sibling_list, but its group_leader pointer is left pointing at the old leader. That is harmless when the sibling is being closed and freed immediately, as in the DETACH_DEAD path. It is not safe when the sibling is detached but kept alive, such as during CPU hotplug with DETACH_GROUP. In that case the sibling is removed from the context, while its file descriptor can still keep it alive. A typical failing sequence is: - A group contains leader L and sibling S. - CPU hot-unplug detaches S with DETACH_GROUP, removing it from L->sibling_list but leaving S->group_leader == L. - L is later closed and freed. - A PERF_IOC_FLAG_GROUP ioctl on S follows S->group_leader and dereferences the freed leader. This was reproduced by running the perf event fuzzer, CPU hotplug, and a stress workload concurrently: Unable to handle kernel paging request at virtual address 006b6b6b6b6b6cdb CPU: 2 PID: 12489 Comm: perf_fuzzer 6.18.7 PREEMPT pc : perf_ioctl+0x34c/0xc68 x20: ffffff89a3fa2c70 x8 : 6b6b6b6b6b6b6b6b Code: 943c4a0e 340047a0 f9404a94 f9411e88 (f940b908) Call trace: perf_ioctl+0x34c/0xc68 (P) __arm64_sys_ioctl+0xa0/0xf4 invoke_syscall+0x58/0xe4 el0_svc_common+0xa8/0xdc do_el0_svc+0x1c/0x28 el0_svc+0x40/0xc0 el0t_64_sync_handler+0x68/0xdc el0t_64_sync+0x1c4/0x1c8 The fault happened in perf_ioctl(), where perf_event_for_each() follows the stale group_leader pointer and perf_event_for_each_child() then dereferences the freed leader's context. Fix the use-after-free by promoting the detached sibling to a singleton. Also fix __event_disable() cgroup accounting and event state change.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

0.00 pp

From 0.13% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.13%

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

Ubuntu169 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.187-1 | < 6.12.105-1 | < 7.1.9-1
  • linux-6.12< 6.12.107-1~deb12u1
Linux1 product
  • linux≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < 8f867c0e8da4c2303d91adf45acb6b1820966c27 | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < 8e92e03984364d93e0d5b0acd81c95eca773f034 | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < f8a07021679aadfb6d63b209207ccc41f26982d1 | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < 80c6054a4c40a0ffad82acef9f9a0dee108d152a | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35 | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < a979a642402d0b1f856c7a729b4cb2d92de4cf2f | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < 1e7abfeb23c12bf46f6457e4a3e1a1a300d50619 | ≥ 8a49542c0554af7d0073aac0ee73ee65b807ef34, < 42c5ca1f0a288a52878bd72a5595b08261057438 | e732ebc42aea321ee84514330eb3a675307fcc83 | ≥ 2.6.34.14, < 2.6.35 | 2.6.35

3 vendors · 172 products

References

13 links
Show all 13 references