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 function Certificate_Store::certificate_known returns true when any certificate in the store matches the DN and subject key identifier of the input certificate, without confirming they are the same certificate. This led to a vulnerability where the path validation logic assumed certificates were identical if certificate_known returned true. Consequently, an end entity certificate with a DN and subject key identifier matching a trusted root certificate could be accepted as a trusted root, bypassing intended validation checks. This improper certificate validation is classified under CWE-295. The vulnerability is resolved in Botan 3.11.1.
Potential Impact
An attacker could present an end entity certificate that shares the distinguished name and subject key identifier of a trusted root certificate, causing the Botan library to accept it as a trusted root. This undermines the trust model of certificate validation, potentially allowing unauthorized certificates to be trusted and enabling man-in-the-middle or impersonation attacks in systems relying on affected Botan versions.
Mitigation Recommendations
This vulnerability is fixed in Botan version 3.11.1. Users should upgrade to version 3.11.1 or later to remediate this issue. No other mitigation or temporary workaround is indicated in the available data.
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Botan 3.11.0, the function Certificate_Store::certificate_known returns true when any certificate in the store matches the DN and subject key identifier of the input certificate, without confirming they are the same certificate. This led to a vulnerability where the path validation logic assumed certificates were identical if certificate_known returned true. Consequently, an end entity certificate with a DN and subject key identifier matching a trusted root certificate could be accepted as a trusted root, bypassing intended validation checks. This improper certificate validation is classified under CWE-295. The vulnerability is resolved in Botan 3.11.1.
Potential Impact
An attacker could present an end entity certificate that shares the distinguished name and subject key identifier of a trusted root certificate, causing the Botan library to accept it as a trusted root. This undermines the trust model of certificate validation, potentially allowing unauthorized certificates to be trusted and enabling man-in-the-middle or impersonation attacks in systems relying on affected Botan versions.
Mitigation Recommendations
This vulnerability is fixed in Botan version 3.11.1. Users should upgrade to version 3.11.1 or later to remediate this issue. No other mitigation or temporary workaround is indicated in the available data.
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
Threat ID: 69d5779eaaed68159a6ad780
Added to database: 4/7/2026, 9:31:10 PM
Last enriched: 4/7/2026, 9:46:17 PM
Last updated: 4/8/2026, 12:43:07 AM
Views: 5
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