CVE-2026-59099
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.
Scoring
- Severity
- CRITICAL
- CVSS base score
- 9.3
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- EPSS probability
- 0.55%
- CWE
- CWE-323
- Published
- 2026-07-02
- Last modified
- 2026-07-14
Affected products
- apereo cas
Weakness type
Related vulnerabilities
- CVE-2026-81341 — wolfEngine reuses the AES-CCM nonce on TLS 1.2 / DTLS 1.2 records
- CVE-2026-81020 — wolfEngine reuses the AES-GCM nonce on every TLS 1.2 / DTLS 1.2 record
- CVE-2026-81019 — wolfProvider reuses the AES-GCM nonce on every TLS 1.2 / DTLS 1.2 record
- CVE-2026-50577 — ePA 3.x Integration: AES-GCM Nonce Reuse via Frozen VAU Request Counter
- CVE-2026-17578 — Kong Event Gateway AES-GCM nonce reuse due to missing key rotation enforcement
- CVE-2026-21383 — Reusing a Nonce, Key Pair in Encryption in HLOS
- CVE-2026-13602 — Session takeover vulnerability
- CVE-2026-56369 — ImageMagick - Information Disclosure via AES-CTR Nonce Reuse in PasskeyEncipherImage