---
id: "CVE-2026-118768"
kind: "vulnerability"
aliases: ["CVE-2026-118768"]
title: "Botan: OCSP check accepts unsigned responses, so revoked certificates pass"
severity: "medium"
cvss: 5.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["botan", "c++", "cryptography", "ocsp", "package"]
not_affected_if: ["library-only-use", "no-ocsp-check-command"]
published_at: "2026-10-29T18:17:28+00:00"
first_seen_at: "2026-10-29T18:26:33+00:00"
updated_at: "2026-10-29T18:28:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118768", "first_seen_at": "2026-10-29T18:26:33+00:00"}]
---

# Botan: OCSP check accepts unsigned responses, so revoked certificates pass

The botan ocsp_check command accepted OCSP responses without verifying their signature, so a revoked certificate could be reported as good. An attacker who can answer the OCSP request or sit on the network path can make a revoked certificate look valid.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `botan version` and see whether it reports a version earlier than `3.13.0`.
- Search build and deployment scripts for `ocsp_check` use.

## Fix

- Botan: upgrade to `3.13.0`.

## Timeline

- 2026-10-29T18:26:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118768

## From the sources

Botan is a C++ cryptography library. From 1.11.34 until 3.13.0, the botan ocsp_check command requested an OCSP response from a certificate's Authority Information Access URL without verifying the response signature or authorizing the signer. A malicious responder or on-path attacker could return a matching and timely GOOD response with an empty, invalid, or unauthorized signature, causing a revoked certificate to produce exit status 0 and OCSP check OK output. Only the command-line interface is affected. This issue is fixed in version 3.13.0.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_