Double-free When Checking OCSP Stapled Response

Summary

CVECVE-2026-35188
StatePUBLISHED
Assigneropenssl
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-09 17:17:05 UTC
Updated2026-06-10 08:16:23 UTC
DescriptionIssue 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.

Risk And Classification

Problem Types: CWE-415 | CWE-415 CWE-415 Double Free

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA OpenSSL OpenSSL affected 4.0.0 4.0.1 semver Not specified
CNA OpenSSL OpenSSL affected 3.6.0 3.6.3 semver Not specified

References

ReferenceSourceLinkTags
github.com/openssl/openssl/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd [email protected] github.com
github.com/openssl/openssl/commit/131145d25659e8749a9ed1afb383484854cffb78 [email protected] github.com
openssl-library.org/news/secadv/20260609.txt [email protected] openssl-library.org
github.com/openssl/security/commit/131145d25659e8749a9ed1afb383484854cffb78 MITRE github.com
github.com/openssl/security/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd MITRE github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Wang Kenaz (University of Illinois) (en)

CNA: Guido Vranken (Aisle Research) (en)

CNA: Aaron Grattafiori (Nvidia) (en)

CNA: Daniel Kubec (en)

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