Answer in brief
CVE-2026-53163 records a Medium severity (CVSS 5.5) vulnerability in locking/rtmutex: Skip remove_waiter() when waiter is not enqueued. The current sources do not mark it as known exploited. The current feed maps 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 5.5. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f3fa3424bceb128d2be4b3745506b22844b87db7 <bfbc047ceb42c0e1fac8f3a155d4548a8bbe76b1 || >=838ce5cb5d93c3ab8b27e75bc6ad905a94b752fd <4ffacf76a457b7ca8ac05f5df8740b0d8f53574a || >=d8cce4773c2b23d819baf5abedc62f7b430e8745 <4afda3a1da02129568a3a2f1898aa13e6763bcba || >=8a1fc8d698ac5e5916e3082a0f74450d71f9611f <6707d7e0b71748cb3cd95bad81dae5fe1b3c8f48 || >=6d52dfcb2a5db86e346cf51f8fcf2071b8085166 <5799f9bd7fee40370b93ab1ddf001cdc7017c14d || >=3fb7394a837740770f0d6b4b30567e60786a63f2 <a388e3dfaf9538a680de5ed43a8ebb5dd45b6e53 || >=88614876370aac8ad1050ad785a4c095ba17ac11 <55363fa0a04524d11efeaadee734d2db1756ed27 || >=3bfdc63936dd4773109b7b8c280c0f3b5ae7d349 <40a25d59e85b3c8709ac2424d44f65610467871e | bfbc047ceb42c0e1fac8f3a155d4548a8bbe76b1, 4ffacf76a457b7ca8ac05f5df8740b0d8f53574a, 4afda3a1da02129568a3a2f1898aa13e6763bcba, 6707d7e0b71748cb3cd95bad81dae5fe1b3c8f48, 5799f9bd7fee40370b93ab1ddf001cdc7017c14d, a388e3dfaf9538a680de5ed43a8ebb5dd45b6e53, 55363fa0a04524d11efeaadee734d2db1756ed27, 40a25d59e85b3c8709ac2424d44f65610467871e |
| Linux/Linuxgeneric | >=6.1.175 <6.1.177 || >=6.6.140 <6.6.144 || >=6.12.86 <6.12.95 || >=6.18.27 <6.18.36 || >=7.0.4 <7.0.13 | 6.1.177, 6.6.144, 6.12.95, 6.18.36, 7.0.13 |
Published upstream
Jun 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 25, 2026
In the Linux kernel, the following vulnerability has been resolved: locking/rtmutex: Skip remove_waiter() when waiter is not enqueued syzbot triggered the following splat in remove_waiter() via FUTEX_CMP_REQUEUE_PI: KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f] class_raw_spinlock_constructor remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561 rt_mutex_start_proxy_lock+0x103/0x120 futex_requeue+0x10e4/0x20d0 __x64_sys_futex+0x34f/0x4d0 task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection, leaving waiter->task nil, where 3bfdc63936dd ("rtmutex: Use waiter::task instead of current in remove_waiter()") made this fatal. Furthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter() upon a successfully grabbing the rtmutex. 1a1fb985f2e2 ("futex: Handle early deadlock return correctly"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock() (where 'ret' was only ever 0 or < 0) into the wrapper. Tighten this check to account for try_to_take_rt_mutex().
Quoted source text, attributed separately from HOL analysis.