CVE-2026-42765 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.
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2026-42765
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.42 Probability of exploitation activity being observed over the next 30 days (34rd percentile)
CVSS score for CVE-2026-42765
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
7.5 High
Products affected by CVE-2026-42765
OpenSSL 3.6.2
OpenSSL 3.6.0
OpenSSL 3.6.1
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Low
More on DVE scores

CVE-2026-42765 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 327 20.17%
DE 168 10.36%
RU 139 8.57%
JP 120 7.40%
CH 69 4.26%
FR 66 4.07%
GB 58 3.58%
CA 56 3.45%
KR 47 2.90%
ES 40 2.47%

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CVE-2026-42765 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 522 52.10%
Telecommunications 278 27.74%
Education 58 5.79%
Government/Politics 37 3.69%
Healthcare/Wellness 19 1.90%
Business Services 16 1.60%
Manufacturing 14 1.40%
Energy/Resources 9 0.90%
Finance 8 0.80%
Transportation 8 0.80%

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