ZDI-26-425: OpenSSL OCSP Stapling Verification Double Free Remote Code Execution Vulnerability
This vulnerability allows remote attackers to execute arbitrary code on affected installations of OpenSSL. User interaction is required to exploit this vulnerability in that the target must make a request to a malicious server. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-35188.
AI Analysis
Technical Summary
CVE-2026-35188 is a high-severity remote code execution vulnerability in OpenSSL caused by a double free error during OCSP stapling verification. The vulnerability arises from improper validation before freeing an object, leading to potential arbitrary code execution. Exploitation requires the victim to interact with a malicious server. OpenSSL has issued a patch to correct this flaw.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary code with the privileges of the OpenSSL process. This can lead to full compromise of the affected application or system component using OpenSSL for OCSP stapling. The vulnerability requires user interaction and network access to a malicious server.
Mitigation Recommendations
OpenSSL has released an official update that fixes this vulnerability. Users and administrators should apply the OpenSSL update as soon as possible to remediate this issue. No additional mitigations are specified by the vendor advisory.
ZDI-26-425: OpenSSL OCSP Stapling Verification Double Free Remote Code Execution Vulnerability
Description
This vulnerability allows remote attackers to execute arbitrary code on affected installations of OpenSSL. User interaction is required to exploit this vulnerability in that the target must make a request to a malicious server. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-35188.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-35188 is a high-severity remote code execution vulnerability in OpenSSL caused by a double free error during OCSP stapling verification. The vulnerability arises from improper validation before freeing an object, leading to potential arbitrary code execution. Exploitation requires the victim to interact with a malicious server. OpenSSL has issued a patch to correct this flaw.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary code with the privileges of the OpenSSL process. This can lead to full compromise of the affected application or system component using OpenSSL for OCSP stapling. The vulnerability requires user interaction and network access to a malicious server.
Mitigation Recommendations
OpenSSL has released an official update that fixes this vulnerability. Users and administrators should apply the OpenSSL update as soon as possible to remediate this issue. No additional mitigations are specified by the vendor advisory.
Technical Details
- Article Source
- {"url":"http://www.zerodayinitiative.com/advisories/ZDI-26-425/","fetched":true,"fetchedAt":"2026-07-16T15:51:04.546Z","wordCount":207}
- Classification
- {"confidence":0.95,"severitySource":"cvss-text","classifier":"rss-v2"}
Threat ID: 6a58fe6668715ace43485bf3
Added to database: 07/16/2026, 15:53:10 UTC
Last enriched: 08/07/2026, 06:03:50 UTC
Last updated: 08/28/2026, 10:52:07 UTC
Views: 72
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