SSRF in Randombit Botan

CVE-2026-118766

Botan is a C++ cryptography library. Prior to 3.13.0, Botan's online OCSP client allowed a single HTTP redirect while posting an OCSP request to the URI in a certificate's Authority Information Access extension. A malicious OCSP responder or an on-path attacker could redirect the client to make one blind request to an otherwise unreachable internal HTTP service. The primary impact is blind SSRF that might affect internal services with non-idempotent GET handlers, and response timing can provide a coarse internal-service oracle. This issue is fixed in version 3.13.0.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-118766?
CVE-2026-118766 is a medium-severity vulnerability in Randombit Botan, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.1/10. Published 2026-10-29.
How severe is CVE-2026-118766?
Medium severity. CVSS v3 base score is 6.1 out of 10.