CVE-2026-59993
Picotls has NULL pointer dereference during handshake, when running as a client
- State
- Published
- Severity
- 6.5 Medium
- Published
- Oct 30, 2026
- Updated
- Oct 30, 2026
- Reserved
- Jul 7, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
- CWE-476 NULL Pointer Dereference
Affected Products
| Product | Versions |
|---|---|
picotlsh2o |
|
References
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