CVE-2026-59099 | BDVDB-2026-345352 Detail
apereocas
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.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact none. Attack vector: network.
Weaknesses#
- CWE-323 Reusing a Nonce, Key Pair in Encryption
References#
- 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
Exploit#
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.