Vulnerability record/PUBLISHED/Published Oct 30, 2026 21:01:54 UTC
CVE-2026-59993
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.
Base score6.5/ 10
SeverityMediumCVSS 3.1
Exploitability / impact
CVSS metric breakdown
Base severityMedium
Attack vectorNetworkAV
Attack complexityLowAC
Privileges requiredNonePR
User interactionRequiredUI
ScopeUnchangedS
Confidentiality impactNoneC
Integrity impactNoneI
Availability impactHighA
CVSS vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HCVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.
Record context
CVE Numbering AuthorityGitHub_M
Last updatedNov 6, 2026 18:24:13 UTC
PublishedOct 30, 2026 21:01:54 UTC
ReservedJul 7, 2026 19:41:00 UTC