{"id":"CVE-2026-59993","published":"2026-10-30T21:17:13.067","lastModified":"2026-10-30T21:17:13.193","description":"Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. In affected revisions through 44bc503, when picotls is used as a `client-side TLS stack`, a peer can send a `HelloRetryRequest` followed by a `spoofed Hello message` that causes a null-pointer dereference. This can terminate the consuming process, including a process performing other work, resulting in denial of service. This issue is fixed in commit a06ca41.","cvssScore":6.5,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","cwes":["CWE-476"],"vendors":[],"products":[],"references":[{"url":"https://github.com/h2o/picotls/commit/a06ca417a16f9126808bf5cabe6c5e6e0f16ecae","tags":[]},{"url":"https://github.com/h2o/picotls/pull/608","tags":[]},{"url":"https://github.com/h2o/picotls/security/advisories/GHSA-2xcv-h2pg-m99c","tags":[]}],"exploitRefs":[{"url":"https://github.com/h2o/picotls/commit/a06ca417a16f9126808bf5cabe6c5e6e0f16ecae","tags":[]},{"url":"https://github.com/h2o/picotls/pull/608","tags":[]},{"url":"https://github.com/h2o/picotls/security/advisories/GHSA-2xcv-h2pg-m99c","tags":[]}],"hasPoc":true,"ai":null}