Vulnerability-Lookup

GHSA-VM8W-J6FW-JC7R

Vulnerability from github – Published: 2026-06-09 18:30 – Updated: 2026-06-10 09:31

Details

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.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-42765"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-09T17:17:07Z",
    "severity": "HIGH"
  },
  "details": "Issue summary: When a partial-chain certificate verification is enabled\ntogether with OCSP response checking for the whole chain, a NULL dereference\nwill happen if the verified chain does not have a self-signed trusted anchor,\ncrashing the process.\n\nImpact summary: A NULL pointer dereference can trigger a crash which leads to a\nDenial of Service for an application.\n\nWhen performing OCSP response checking for certificates in the verification\nchain, the code always tries to access the next certificate as the issuer.\nThere is a check for a self-signed certificate. However with the partial\nchain verification enabled when the chain does not have a self-signed trusted\nanchor, the issuer will be NULL for the last certificate in the chain. A NULL\npointer dereference then happens.\n\nThis issue affects only applications which enable both OCSP verification\nof the certificate chain (X509_V_FLAG_OCSP_RESP_CHECK_ALL) and partial\nchain verification (X509_V_FLAG_PARTIAL_CHAIN) in the certificate\nverification. Both flags are disabled by default. For that reason, we have\nassigned Low severity to the issue.\n\nNo FIPS modules are affected by this issue as the affected code is outside\nthe OpenSSL FIPS module boundary.",
  "id": "GHSA-vm8w-j6fw-jc7r",
  "modified": "2026-06-10T09:31:56Z",
  "published": "2026-06-09T18:30:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42765"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/14340b7fa1d444615486bc137014b064e64ec334"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/openssl/commit/eb345da18ce2216b2f3ade9c2bc23e068487fa97"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/security/commit/14340b7fa1d444615486bc137014b064e64ec334"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openssl/security/commit/eb345da18ce2216b2f3ade9c2bc23e068487fa97"
    },
    {
      "type": "WEB",
      "url": "https://openssl-library.org/news/secadv/20260609.txt"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-42765 (GCVE-0-2026-42765)

Vulnerability from cvelistv5 – Published: 2026-06-09 16:03 – Updated: 2026-06-10 07:48

Title

NULL Dereference in Certificate Verification with OCSP Checking

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 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.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-476 - NULL Pointer Dereference

Assigner

openssl

References

3 references

URL	Tags
https://openssl-library.org/news/secadv/20260609.txt	vendor-advisory
https://github.com/openssl/openssl/commit/14340b7…	patch
https://github.com/openssl/openssl/commit/eb345da…	patch

Impacted products

1 product

Vendor	Product	Version
OpenSSL	OpenSSL	Affected: 4.0.0 , < 4.0.1 (semver) Affected: 3.6.0 , < 3.6.3 (semver)

Date Public

2026-06-09 14:00

Credits

Joshua Rogers (Aisle Research) Joshua Rogers (Aisle Research) Daniel Kubec

Show details on NVD website

JSON

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              "attackVector": "NETWORK",
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              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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                  },
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                  }
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                "role": "CISA Coordinator",
                "timestamp": "2026-06-09T19:35:48.849695Z",
                "version": "2.0.3"
              },
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            }
          }
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        "providerMetadata": {
          "dateUpdated": "2026-06-09T19:36:06.889Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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          "vendor": "OpenSSL",
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              "status": "affected",
              "version": "4.0.0",
              "versionType": "semver"
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-VM8W-J6FW-JC7R

CVE-2026-42765 (GCVE-0-2026-42765)

Tags

Sightings

Nomenclature