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OpenAdvisories
Medium · 5.0 CVE-2026-35188 EUVD-2026-35480GHSA-vc8w-w49c-4jgj

Double-free When Checking OCSP Stapled Response

Published Jun 9, 2026 · Updated Jun 10, 2026 · Assigned by openssl

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.

Affected products

VendorProductAffectedFixed
OpenSSL OpenSSL 4.0.0 – < 4.0.1, 3.6.0 – < 3.6.3 4.0.1

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 openssl 3.6.3-1 —
ReleasePackageFixed inAdvisory
Ubuntu Pro 22.04 LTS nodejs No fix yet —
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 bootupd +1 0.3.2-1.hum1 RHSA-2026:67551
Red Hat Hardened Images 1 chunkah 0.6.0-3.hum1 RHSA-2026:42825
Red Hat Hardened Images 1 openssl +10 3.5.8-0.1.hum1 RHSA-2026:59641, RHSA-2026:59635
Red Hat Hardened Images 1 python-cryptography +1 50.0.0-1.hum1 RHSA-2026:55543
Red Hat Hardened Images 1 ruby3.3 +5 3.3.10-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 ruby3.4 +5 3.4.10-31.7.hum1 RHSA-2026:62790
Red Hat Hardened Images 1 ruby4.0 +5 4.0.6-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem3.3-bigdecimal 3.1.5-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-bundler 2.5.22-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-devel +1 3.5.22-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-io-console 0.7.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-irb 1.13.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-json 2.7.2-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-minitest 5.20.0-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-power_assert 2.0.3-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-psych 5.1.2-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-racc 1.7.3-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rake 13.1.0-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rbs 3.4.0-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rdoc 6.6.3.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rexml 3.4.4-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rss 0.3.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-test-unit 3.6.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-typeprof 0.21.9-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem4.0-bigdecimal 4.0.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-devel +2 4.0.16-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-io-console 0.8.2-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-irb 1.16.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-json 2.18.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-minitest 6.0.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-power_assert 3.0.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-psych 5.3.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-racc 1.8.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rake 13.3.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rbs 3.10.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rdoc 7.0.4-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rexml 3.4.4-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rss 0.3.2-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-test-unit 3.7.5-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-typeprof 0.31.1-37.3.hum1 RHSA-2026:62563

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling openssl +1 3.6.3-r0 —
Wolfi rolling openssl-4.0 +2 4.0.1-r0 —

Advisories 10

References