CVE-2026-59099 (GCVE-0-2026-59099)
Vulnerability from cvelistv5 – Published: 2026-07-02 19:42 – Updated: 2026-07-14 22:03 X_Open Source
VLAI
EPSS
VEX
Title
Apereo CAS 7.3.0 < 8.0.0-RC6 - AES-GCM Nonce Reuse Information Disclosure
Summary
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.
Severity
9.1 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-06 12:29 UTC
CWE
- CWE-323 - Reusing a Nonce, Key Pair in Encryption
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://apereo.github.io/2026/06/18/vuln/ | vendor-advisory |
| https://github.com/apereo/cas/releases/tag/v8.0.0-RC6 | release-notes |
| https://github.com/geo-chen/oss/blob/main/cas.md | technical-descriptionexploit |
| https://github.com/apereo/cas/commit/22c6f4adf738… | patch |
| https://www.vulncheck.com/advisories/apereo-cas-r… | third-party-advisory |
Impacted products
Date Public
2026-06-18 00:00
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