Linux Kernel up to 6.18.24/7.0.1 krb5enc_dispatch_decrypt comparison

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.24/7.0.1 and classified as critical. Affected by this vulnerability is the function krb5enc_dispatch_decrypt. Such manipulation leads to comparison. This vulnerability is uniquely identified as CVE-2026-31719. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.24/7.0.1. It has been rated as critical. Affected by this issue is the function krb5enc_dispatch_decrypt. The manipulation with an unknown input leads to a comparison vulnerability. Using CWE to declare the problem leads to CWE-697. The product compares two entities in a security-relevant context, but the comparison is incorrect, which may lead to resultant weaknesses. The impact remains unknown. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-31719 since 03/09/2026. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/30/2026).

Upgrading to version 6.18.25, 7.0.2 or 7.1-rc1 eliminates this vulnerability. Applying the patch 07cbb1bd424370671814a862913c99a6e1441588/e51f42114abbdf47f29dda43e7826be28907fcd2/3bfbf5f0a99c991769ec562721285df7ab69240b is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1346). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Microsoft Azure Linux
• Red Hat OpenShift

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 7.0.0
• 7.0.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Threat Intelligenceinfo

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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