CVE-2026-42765

Published: Giu 09, 2026 Last Modified: Giu 15, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,5
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high

Description

AI Translation Available

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.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0003
Percentile
0,1th
Updated

EPSS Score Trend (Last 7 Days)

476

NULL Pointer Dereference

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Integrity Confidentiality
Potential Impacts:
Dos: Crash, Exit, Or Restart Execute Unauthorized Code Or Commands Read Memory Modify Memory
Applicable Platforms
Languages: C, C++, Java, C#, Go
Likelihood of Exploit: Medium
View CWE Details
Application

Openssl by Openssl

Product Information
Vendor Openssl
Product Openssl
Version 4.0.0
cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Openssl by Openssl

Product Information
Vendor Openssl
Product Openssl
Version Range Affected
From 3.6.0 (inclusive)
To 3.6.3 (exclusive)
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://github.com/openssl/openssl/commit/14340b7fa1d444615…
https://github.com/openssl/openssl/commit/14340b7fa1d444615486bc137014b064e64ec…
https://github.com/openssl/openssl/commit/eb345da18ce2216b2…
https://github.com/openssl/openssl/commit/eb345da18ce2216b2f3ade9c2bc23e068487f…
https://openssl-library.org/news/secadv/20260609.txt
https://openssl-library.org/news/secadv/20260609.txt