CVE-2026-59993

Picotls has NULL pointer dereference during handshake, when running as a client

Published Oct 30, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Picotls has NULL pointer dereference during handshake, when running as a client
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Subscriptions

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Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 6, 2026, 6:24 PM
Reserved
Jul 7, 2026, 7:41 PM
Status
Deferred
Published
Oct 30, 2026, 9:17 PM
Modified
Nov 6, 2026, 7:17 PM