CVE-2026-46033

In the Linux kernel, the following vulnerability has been resolved: crypto: authencesn - reject short ahash digests during instance creation authencesn requires either a zero authsize or an authsize of at least 4 bytes because the ESN encrypt/decrypt paths always move 4 bytes of high-order sequence number data at the end of the authenticated data. While crypto_authenc_esn_setauthsize() already rejects explicit non-zero authsizes in the range 1..3, crypto_authenc_esn_create() still copied auth->digestsize into inst->alg.maxauthsize without validating it. The AEAD core then initialized the tfm's default authsize from that value. As a result, selecting an ahash with digest size 1..3, such as cbcmac(cipher_null), exposed authencesn instances whose default authsize was invalid even though setauthsize() would have rejected the same value. AF_ALG could then trigger the ESN tail handling with a too-short tag and hit an out-of-bounds access. Reject authencesn instances whose ahash digest size is in the invalid non-zero range 1..3 so that no tfm can inherit an unsupported default authsize.

• linux linux kernel (>= 4.11 < 5.10.258) • linux linux kernel (>= 5.11 < 5.15.209) • linux linux kernel (>= 5.16 < 6.1.175) • linux linux kernel (>= 6.2 < 6.6.140) • linux linux kernel (>= 6.7 < 6.12.86) • linux linux kernel (>= 6.13 < 6.18.27) • linux linux kernel (>= 6.19 < 7.0.4) • linux linux kernel 7.1