CVE-2026-82454

The Omnivore API (packages/api) before the fix in commit abf53d6 contains an authentication bypass in Apple sign-in token verification. The decodeAppleToken function extracted the 'alg' field from the attacker-supplied JWT header and passed it as the sole allowed algorithm to jwt.verify(). Using jsonwebtoken v8 (which does not validate key/algorithm compatibility), an attacker can set alg=HS256 and sign a forged token using Apple's publicly available RSA public key as the HMAC secret, bypassing signature verification and impersonating any Apple-linked account.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

• https://github.com/omnivore-app/omnivore
• https://github.com/omnivore-app/omnivore/commit/abf53d6508755d3d22a994e28e370a9193ea977a
• https://github.com/omnivore-app/omnivore/pull/4652
• https://www.vulncheck.com/advisories/omnivore-before-android-0.227.0-authentication-bypass-via-apple-sign-in