CVE-2026-35188 Affecting openssl package, versions <3.6.3-r0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CHAINGUARDLATEST-OPENSSL-17311135
- published12 Jun 2026
- disclosed9 Jun 2026
Introduced: 9 Jun 2026
NewCVE-2026-35188 (opens in a new tab)How to fix?
Upgrade Chainguard openssl to version 3.6.3-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by Chainguard.
See How to fix? for Chainguard relevant fixed versions and status.
Issue summary: A malicious server can exploit TLS OCSP stapling by delivering a crafted response through the status_request extension, triggering a double-free in the client's certificate verification path.
Impact summary: Successful exploitation allows an attacker to corrupt heap memory via a double-free, potentially leading to a Denial of Service or possibly an attacker controlled code execution or other undefined behavior.
If OCSP stapling is enabled and the TLS client connects to a malicious server, a crafted OCSP stapled response can trigger a double free in the TLS client when the stapled response is checked.
The OCSP stapling is not enabled by default. Reliable code execution through a double-free is technically complex and highly environment-dependent but the Denial of Service impact is straightforward to achieve, warranting Moderate severity.
No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.
References
- https://github.com/openssl/security/commit/131145d25659e8749a9ed1afb383484854cffb78
- https://github.com/openssl/security/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd
- https://github.com/openssl/openssl/commit/131145d25659e8749a9ed1afb383484854cffb78
- https://github.com/openssl/openssl/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd
- https://openssl-library.org/news/secadv/20260609.txt