CVE-2026-59099
CRITICALCVSS v3.1: 9.1
Source data as of:
At a glance
- Severity
- CRITICAL
- CVSS
- 9.1 v3.1 · NVD
- EPSS
- EPSS not provided by FIRST.org for this CVE
- CISA KEV
- No
- Attack conditions (CVSS vector)
- NetworkNo privilegesNo user interaction · Source: NVD Vector
- Published
- 2026-07-02 · Modified: 2026-07-02
- References
- Jump to references (5)
CVSS / EPSS / KEV
Source — CVSS: NVD · EPSS: FIRST.org · KEV: CISA. Data & Sources
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.
References
Reference URLs as listed by NVD, grouped by a mechanical match on the link's host/pattern. Labels describe the link type only.
- Reference https://apereo.github.io/2026/06/18/vuln/
- Patch https://github.com/apereo/cas/commit/22c6f4adf738852782309b523b4e80371057f2d0
- Patch https://github.com/apereo/cas/releases/tag/v8.0.0-RC6
- Reference https://github.com/geo-chen/oss/blob/main/cas.md
- Vendor advisory https://www.vulncheck.com/advisories/apereo-cas-rc6-aes-gcm-nonce-reuse-information-disclo…