---
id: CVE-2026-31719
title: 'crypto: krb5enc - fix async decrypt skipping hash verification'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  crypto: krb5enc - fix async decrypt skipping hash verification

  krb5enc_dispatch_decrypt() sets req->base.complete as the skcipher
  callback, which is the caller's own c…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d1775a177f7f38156d541c8a3e3c91eaa6e69699 <
    07cbb1bd424370671814a862913c99a6e1441588
  - >-
    Linux >= d1775a177f7f38156d541c8a3e3c91eaa6e69699 <
    e51f42114abbdf47f29dda43e7826be28907fcd2
  - >-
    Linux >= d1775a177f7f38156d541c8a3e3c91eaa6e69699 <
    3bfbf5f0a99c991769ec562721285df7ab69240b
  - Linux 6.15
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T15:12:50.260721Z'
published: '2026-05-01'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:20:25.520Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31719'
references:
  - url: 'https://git.kernel.org/stable/c/07cbb1bd424370671814a862913c99a6e1441588'
  - url: 'https://git.kernel.org/stable/c/e51f42114abbdf47f29dda43e7826be28907fcd2'
  - url: 'https://git.kernel.org/stable/c/3bfbf5f0a99c991769ec562721285df7ab69240b'
tags:
  - cve.org
epss: 0.00506
epssPercentile: 0.41885
ingestedAt: '2026-10-16T17:24:46.672Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

crypto: krb5enc - fix async decrypt skipping hash verification

krb5enc_dispatch_decrypt() sets req->base.complete as the skcipher
callback, which is the caller's own completion handler. When the
skcipher completes asynchronously, this signals "done" to the caller
without executing krb5enc_dispatch_decrypt_hash(), completely bypassing
the integrity verification (hash check).

Compare with the encrypt path which correctly uses
krb5enc_encrypt_done as an intermediate callback to chain into the
hash computation on async completion.

Fix by adding krb5enc_decrypt_done as an intermediate callback that
chains into krb5enc_dispatch_decrypt_hash() upon async skcipher
completion, matching the encrypt path's callback pattern.

Also fix EBUSY/EINPROGRESS handling throughout: remove
krb5enc_request_complete() which incorrectly swallowed EINPROGRESS
notifications that must be passed up to callers waiting on backlogged
requests, and add missing EBUSY checks in krb5enc_encrypt_ahash_done
for the dispatch_encrypt return value.


Unset MAY_BACKLOG on the async completion path so the user won't
see back-to-back EINPROGRESS notifications.

## Affected

- `Linux >= d1775a177f7f38156d541c8a3e3c91eaa6e69699 < 07cbb1bd424370671814a862913c99a6e1441588`
- `Linux >= d1775a177f7f38156d541c8a3e3c91eaa6e69699 < e51f42114abbdf47f29dda43e7826be28907fcd2`
- `Linux >= d1775a177f7f38156d541c8a3e3c91eaa6e69699 < 3bfbf5f0a99c991769ec562721285df7ab69240b`
- `Linux 6.15`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.