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CVE-2026-59993 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

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.

Metrics

CVSS 3.x Severity and Vector Strings:

VolerionCVSS-B:6.5 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CNA: [email protected]CVSS-B:6.5 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://github.com/h2o/picotls/commit/a06ca417a16f9126808bf5cabe6c5e6e0f16ecae	[email protected]	Source CodeVendor
https://github.com/h2o/picotls/pull/608	[email protected]	Source CodeVendor
https://github.com/h2o/picotls/security/advisories/GHSA-2xcv-h2pg-m99c	[email protected]	AdvisoryRemedyVendor

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-476	NULL Pointer Dereference	[email protected]

Affected Products

Product	Versions
h2o picotls	<= 44bc503
CPE No CPEs found in CPE dictionary for this product. Remediation Upgrade: a06ca41moderate effort

Change History

2 change records found show changes

Date	Action	Recorded By
Nov 6, 2026	CVE Modified	CISA-ADP
Oct 30, 2026	New CVE Received	[email protected]