CVE-2026-34580: CWE-295: Improper Certificate Validation in randombit botan
Botan is a C++ cryptography library. In 3.11.0, the function Certificate_Store::certificate_known had a misleading name; it would return true if any certificate in the store had a DN (and subject key identifier, if set) matching that of the argument. It did not check that the cert it found and the cert it was passed were actually the same certificate. In 3.11.0 an extension of path validation logic was made which assumed that certificate_known only returned true if the certificates were in fact identical. The impact is that if an end entity certificate is presented, and its DN (and subject key identifier, if set) match that of any trusted root, the end entity certificate is accepted immediately as if it itself were a trusted root. , This vulnerability is fixed in 3.11.1.
AI Analysis
Technical Summary
In Botan 3.11.0, the Certificate_Store::certificate_known function returns true when any certificate in the store matches the DN and subject key identifier of the input certificate, without confirming the certificates are identical. The path validation logic assumes certificate_known only returns true for identical certificates, leading to acceptance of an end entity certificate as a trusted root if it shares DN and subject key identifier with a trusted root. This improper certificate validation (CWE-295) can cause trust bypass. The vulnerability is resolved in Botan 3.11.1.
Potential Impact
An attacker can present an end entity certificate that shares the DN and subject key identifier with a trusted root certificate, causing the library to accept it immediately as a trusted root. This undermines the trust model of certificate validation, potentially allowing unauthorized certificates to be trusted and compromising secure communications relying on Botan.
Mitigation Recommendations
A fix is available in Botan version 3.11.1. Users should upgrade to version 3.11.1 or later to remediate this vulnerability. Patch status is confirmed by the vendor advisory. No additional mitigation steps are indicated.
CVE-2026-34580: CWE-295: Improper Certificate Validation in randombit botan
Description
Botan is a C++ cryptography library. In 3.11.0, the function Certificate_Store::certificate_known had a misleading name; it would return true if any certificate in the store had a DN (and subject key identifier, if set) matching that of the argument. It did not check that the cert it found and the cert it was passed were actually the same certificate. In 3.11.0 an extension of path validation logic was made which assumed that certificate_known only returned true if the certificates were in fact identical. The impact is that if an end entity certificate is presented, and its DN (and subject key identifier, if set) match that of any trusted root, the end entity certificate is accepted immediately as if it itself were a trusted root. , This vulnerability is fixed in 3.11.1.
CVSS v4.0
Score 9.3critical
Affected software
pkg:github/randombit/botanRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Botan 3.11.0, the Certificate_Store::certificate_known function returns true when any certificate in the store matches the DN and subject key identifier of the input certificate, without confirming the certificates are identical. The path validation logic assumes certificate_known only returns true for identical certificates, leading to acceptance of an end entity certificate as a trusted root if it shares DN and subject key identifier with a trusted root. This improper certificate validation (CWE-295) can cause trust bypass. The vulnerability is resolved in Botan 3.11.1.
Potential Impact
An attacker can present an end entity certificate that shares the DN and subject key identifier with a trusted root certificate, causing the library to accept it immediately as a trusted root. This undermines the trust model of certificate validation, potentially allowing unauthorized certificates to be trusted and compromising secure communications relying on Botan.
Mitigation Recommendations
A fix is available in Botan version 3.11.1. Users should upgrade to version 3.11.1 or later to remediate this vulnerability. Patch status is confirmed by the vendor advisory. No additional mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-30T16:56:30.999Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-34580","vendor":"Red Hat"}]
Threat ID: 69d5779eaaed68159a6ad780
Added to database: 04/07/2026, 21:31:10 UTC
Last enriched: 07/15/2026, 09:03:08 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 193
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