---
schema_version: '1.0'
id: security-20260705-8ecc35
url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-42765
url_hash: 8ecc35442f3e3bfd1af3ce1b1fe374f97c9113e7f881a171a051751f948e2d73
canonical_url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-42765
source: osv:debian
category: security/os
category_raw: cve/os
region: null
tags:
- cve
- DEBIAN-CVE-2026-42765
- severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- openssl
- Debian
lang: en
published_at: '2026-06-09T17:17:07Z'
fetched_at: '2026-07-05T15:34:34Z'
updated_at: '2026-07-05T15:36:30Z'
status: published
content_hash: cfd987036b2078e510be78e1ca3c107b5008cc830eda4c6340d1f483ee67f1e3
license_note: full
summary: 'Issue summary: When a partial-chain certificate verification is enabled
  together with OCSP response checking for the whole chain, a NULL dereference will
  happen if the verified chain does not have a self-signed trusted anchor, crashing
  the process.  Impact summary: A NULL pointer'
summary_source: rss
summary_en: 'Issue summary: When a partial-chain certificate verification is enabled
  together with OCSP response checking for the whole chain, a NULL dereference will
  happen if the verified chain does not have a self-signed trusted anchor, crashing
  the process.  Impact summary: A NULL pointer'
entities: []
key_facts: []
related: []
related_auto: []
title: DEBIAN-CVE-2026-42765 — openssl
---

# DEBIAN-CVE-2026-42765 — openssl

## TL;DR
Issue summary: When a partial-chain certificate verification is enabled together with OCSP response checking for the whole chain, a NULL dereference will happen if the verified chain does not have a self-signed trusted anchor, crashing the process.  Impact summary: A NULL pointer

## Key Points
- cve / DEBIAN-CVE-2026-42765 / severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H / openssl / Debian

## Details
**Severity:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
**Advisory:** DEBIAN-CVE-2026-42765

**Affected (your watchlist):**
- `Debian:openssl` 3.0.11-1~deb12u2 → no fixed version listed [rpi]

**Details:**
Issue summary: When a partial-chain certificate verification is enabled together with OCSP response checking for the whole chain, a NULL dereference will happen if the verified chain does not have a self-signed trusted anchor, crashing the process.  Impact summary: A NULL pointer dereference can trigger a crash which leads to a Denial of Service for an application.  When performing OCSP response checking for certificates in the verification chain, the code always tries to access the next certificate as the issuer. There is a check for a self-signed certificate. However with the partial chain verification enabled when the chain does not have a self-signed trusted anchor, the issuer will be NULL for the last certificate in the chain. A NULL pointer dereference then happens.  This issue affects only applications which enable both OCSP verification of the certificate chain (X509_V_FLAG_OCSP_RESP_CHECK_ALL) and partial chain verification (X509_V_FLAG_PARTIAL_CHAIN) in the certificate verification. Both flags are disabled by default. For that reason, we have assigned Low severity to the issue.  No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.

**References:**
- https://security-tracker.debian.org/tracker/CVE-2026-42765

_Data: OSV.dev (upstream: debian) — https://osv.dev/vulnerability/DEBIAN-CVE-2026-42765_

## Source
元記事: [DEBIAN-CVE-2026-42765 — openssl](https://osv.dev/vulnerability/DEBIAN-CVE-2026-42765) — published 2026-06-09T17:17:07Z