CVE-2026-46033: crypto: authencesn - reject short ahash digests during instance creation
crypto: authencesn - reject short ahash digests during instance creation
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.141.1-1 - Upgrade
Upgrade
Linux kernel crypto: authencesnto a version that resolves this vulnerability.Patch crypto: authencesn - reject short ahash digests during instance creation
Event History
Frequently Asked Questions
What conditions are required to trigger the out-of-bounds access?
An authencesn instance must be created with an ahash whose digest size is 1 to 3 bytes, causing an unsupported default authentication tag size. AF_ALG can then invoke the ESN tail handling using that too-short tag.
Are configurations using a zero-byte authentication size affected?
No. authencesn supports an authsize of zero; the invalid non-zero range is 1 through 3 bytes.
How can I determine whether an exposed authencesn instance exists?
Check whether authencesn can be instantiated with an ahash reporting a digest size of 1 to 3 bytes, such as cbcmac(cipher_null). Such an instance may inherit an invalid default authsize even though explicitly setting that authsize would be rejected.
What does the fix change?
The fix rejects creation of authencesn instances when the selected ahash has a non-zero digest size from 1 to 3 bytes. This prevents a transform from inheriting an unsupported default authentication size.