CVE-2026-64312

Analyzed Analyzed - Analysis Complete

Linux Kernel pcrypt Parallel Fallback Callback Issue

Publication date: 2026-07-25

Last updated on: 2026-09-03

Assigner: kernel.org

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-25

Last Modified

2026-09-03

Generated

2026-09-23

AI Q&A

2026-07-25

EPSS Evaluated

2026-09-22

NVD

CVE-2026-64312

EUVD

EUVD-2026-49024

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 4.19.325 (inc) to 4.20 (exc)
linux	linux_kernel	From 5.4.287 (inc) to 5.5 (exc)
linux	linux_kernel	From 6.11.11 (inc) to 6.12 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.39 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.1.4 (exc)
linux	linux_kernel	From 5.10.231 (inc) to 5.10.261 (exc)
linux	linux_kernel	From 5.15.174 (inc) to 5.15.212 (exc)
linux	linux_kernel	From 6.1.120 (inc) to 6.1.178 (exc)
linux	linux_kernel	From 6.12.2 (inc) to 6.12.96 (exc)
linux	linux_kernel	From 6.6.64 (inc) to 6.6.145 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a flaw in the pcrypt module's fallback mechanism for AEAD (Authenticated Encryption with Associated Data) requests. When padata_do_parallel() returns -EBUSY, pcrypt attempts to process the request directly without removing a previously set completion callback. This can lead to an asynchronous completion running pcrypt_aead_done() even though the request was never properly enrolled in padata.

Detection Guidance

This vulnerability is specific to the Linux kernel's pcrypt module and does not have direct network or system detection commands. It requires kernel code inspection or monitoring for crashes related to AEAD operations. Check kernel logs for errors in crypto or padata subsystems.

Impact Analysis

This vulnerability could cause unexpected behavior in cryptographic operations, potentially leading to data corruption or security issues if the callback is executed incorrectly. Systems relying on pcrypt for parallel cryptographic processing may experience crashes or incorrect encryption/decryption results.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it pertains to a low-level cryptographic subsystem in the Linux kernel. No evidence suggests data exposure or unauthorized access risks that would violate these regulations.

Mitigation Strategies

Apply the latest Linux kernel patches that address this issue. Monitor vendor advisories for updates to your distribution. If you cannot patch immediately, disable pcrypt or restrict AEAD operations until patched.

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