CVE-2026-35188

Public on 2026-06-09
Modified on 2026-06-11
Description
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.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
5.9
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core edk2 Not Affected
Amazon Linux 2 - Core openssl Not Affected
Amazon Linux 2023 openssl Not Affected
Amazon Linux 2 - Openssl-snapsafe Extra openssl-snapsafe Not Affected
Amazon Linux 2 - Core openssl11 Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H