Description
Apereo CAS 7.3.0 before 8.0.0-RC6 contains a cryptographic vulnerability that allows remote unauthenticated attackers to recover plaintext conversation state by exploiting AES-GCM initialization vector reuse across the server lifetime. Attackers can collect multiple client-side webflow execution tokens from the unauthenticated login page and perform known-plaintext analysis to decrypt the webflow conversation state due to keystream reuse caused by a fixed all-zero IV paired with the same encryption key.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
apereo cas
Default version status: unaffected
7.3.0 to < 8.0.0-RC6affected
pkg:github/apereo/casReferences
- https://apereo.github.io/2026/06/18/vuln/ ↗
- https://github.com/apereo/cas/releases/tag/v8.0.0-RC6 ↗
- https://github.com/geo-chen/oss/blob/main/cas.md ↗
- https://github.com/apereo/cas/commit/22c6f4adf738852782309b523b4e80371057f2d0 ↗
- https://www.vulncheck.com/advisories/apereo-cas-rc6-aes-gcm-nonce-reuse-information-disclosure ↗