Answer in brief
CVE-2026-74637 records a High severity (CVSS 7.8) vulnerability in perf/core: Fix group leader use-after-free after sibling detach. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 2.6.35 | Not reported |
| Linux/Linuxgeneric | >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <a979a642402d0b1f856c7a729b4cb2d92de4cf2f || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <1e7abfeb23c12bf46f6457e4a3e1a1a300d50619 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <42c5ca1f0a288a52878bd72a5595b08261057438 || e732ebc42aea321ee84514330eb3a675307fcc83 || >=2.6.34.14 <2.6.35 | a979a642402d0b1f856c7a729b4cb2d92de4cf2f, 1e7abfeb23c12bf46f6457e4a3e1a1a300d50619, 42c5ca1f0a288a52878bd72a5595b08261057438, 2.6.35 |
| Linux/Linuxgeneric | >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <a979a642402d0b1f856c7a729b4cb2d92de4cf2f || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <1e7abfeb23c12bf46f6457e4a3e1a1a300d50619 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <42c5ca1f0a288a52878bd72a5595b08261057438 || e732ebc42aea321ee84514330eb3a675307fcc83 || >=2.6.34.14 <2.6.35 | b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35, a979a642402d0b1f856c7a729b4cb2d92de4cf2f, 1e7abfeb23c12bf46f6457e4a3e1a1a300d50619, 42c5ca1f0a288a52878bd72a5595b08261057438, 2.6.35 |
| Linux/Linuxgeneric | >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <8f867c0e8da4c2303d91adf45acb6b1820966c27 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <8e92e03984364d93e0d5b0acd81c95eca773f034 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <f8a07021679aadfb6d63b209207ccc41f26982d1 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <80c6054a4c40a0ffad82acef9f9a0dee108d152a || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <a979a642402d0b1f856c7a729b4cb2d92de4cf2f || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <1e7abfeb23c12bf46f6457e4a3e1a1a300d50619 || >=8a49542c0554af7d0073aac0ee73ee65b807ef34 <42c5ca1f0a288a52878bd72a5595b08261057438 || e732ebc42aea321ee84514330eb3a675307fcc83 || >=2.6.34.14 <2.6.35 | 8f867c0e8da4c2303d91adf45acb6b1820966c27, 8e92e03984364d93e0d5b0acd81c95eca773f034, f8a07021679aadfb6d63b209207ccc41f26982d1, 80c6054a4c40a0ffad82acef9f9a0dee108d152a, b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35, a979a642402d0b1f856c7a729b4cb2d92de4cf2f, 1e7abfeb23c12bf46f6457e4a3e1a1a300d50619, 42c5ca1f0a288a52878bd72a5595b08261057438, 2.6.35 |
Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 22, 2026
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.
Quoted source text, attributed separately from HOL analysis.