# CVE-2026-53352: signal: clear JOBCTL_PENDING_MASK for caller in zap_other_threads()

> A race condition in the Linux kernel signal handling can trigger a kernel warning and potential denial of service when execve races with group stop.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Jul 2026
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2026-53352, DEBIAN-CVE-2026-53352, GHSA-hcpv-6hqv-vmx5, ROOT-OS-UBUNTU-2204-CVE-2026-53352, ROOT-OS-UBUNTU-2404-CVE-2026-53352, UBUNTU-CVE-2026-53352

## What is CVE-2026-53352?

CVE-2026-53352 is a medium-severity vulnerability in Linux kernel, published on 1 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

signal: clear JOBCTL_PENDING_MASK for caller in zap_other_threads()

When a multi-threaded process receives a stop signal (e.g., SIGSTOP),
do_signal_stop() sets JOBCTL_STOP_PENDING and JOBCTL_STOP_CONSUME on all
threads and sets signal->group_stop_count to the number of threads. If
one of the threads concurrently calls execve(), de_thread() invokes
zap_other_threads() to kill all other threads. zap_other_threads()
aborts the pending group stop by resetting signal->group_stop_count to 0
and clears the JOBCTL_PENDING_MASK for all other threads. However, it
fails to clear the job control flags for the calling thread.

When execve() completes, the calling thread returns to user mode and
checks for pending signals. Seeing the stale JOBCTL_STOP_PENDING flag,
it calls do_signal_stop(), which invokes task_participate_group_stop().
Since JOBCTL_STOP_CONSUME is still set, it attempts to decrement the
already-zero signal->group_stop_count, triggering a warning:

sig->group_stop_count == 0
WARNING: CPU: 1 PID: 6475 at kernel/signal.c:373
task_participate_group_stop+0x215/0x2d0
Call Trace:
 <TASK>
 do_signal_stop+0x3be/0x5c0 kernel/signal.c:2619
 get_signal+0xa8c/0x1330 kernel/signal.c:2884
 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
 </TASK>

Fix this race condition by clearing the JOBCTL_PENDING_MASK for the
calling thread in zap_other_threads(), ensuring it does not retain any
stale job control state after the thread group is destroyed. This aligns
with other functions that tear down a thread group and abort group
stops, such as zap_process() and complete_signal(), which correctly
clear these flags for all threads including the current one.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-53352?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53352?

Apply the vendor's patch.

## Is CVE-2026-53352 being exploited?

There is no known exploitation of CVE-2026-53352 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53352 and fix it if it is affected.

What it is: CVE-2026-53352 is a medium-severity vulnerability in Linux kernel, published on 1 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53352 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53352/ (Markdown: https://insights.sbomify.com/CVE-2026-53352/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53352
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53352
- OSV: https://osv.dev/vulnerability/CVE-2026-53352

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53352/
Summaries are generated and may contain mistakes; the official description above is the record.