{"id":"CVE-2026-59099","summary":"Apereo CAS 7.3.0 \u003c 8.0.0-RC6 - AES-GCM Nonce Reuse Information Disclosure","details":"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.","modified":"2026-07-16T03:31:01.815859367Z","published":"2026-07-02T19:42:51.897Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59099.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-323"]},"references":[{"type":"ADVISORY","url":"https://apereo.github.io/2026/06/18/vuln/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59099.json"},{"type":"ADVISORY","url":"https://github.com/apereo/cas/releases/tag/v8.0.0-RC6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59099"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/apereo-cas-rc6-aes-gcm-nonce-reuse-information-disclosure"},{"type":"FIX","url":"https://github.com/apereo/cas/commit/22c6f4adf738852782309b523b4e80371057f2d0"},{"type":"PACKAGE","url":"https://github.com/apereo/cas"},{"type":"EVIDENCE","url":"https://github.com/geo-chen/oss/blob/main/cas.md"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/apereo/cas","events":[{"introduced":"7eaf9bbefb8acc431e8fe2da1d3692eb16dee60b"},{"fixed":"3ed874463a24f2a2dc130015ebb4ecd0540f7ef9"},{"fixed":"22c6f4adf738852782309b523b4e80371057f2d0"}],"database_specific":{"source":["DESCRIPTION","REFERENCES"],"extracted_events":[{"introduced":"7.3.0"},{"fixed":"8.0.0-RC6"}]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59099.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}