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
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| 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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openssl | 3.6.3-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | nodejs | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | openssl +1 | 3.6.3-r0 | — |
| Wolfi rolling | openssl-4.0 +2 | 4.0.1-r0 | — |
Advisories 10
- WID-SEC-2026-2455 Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- WID-SEC-2026-1852 OpenSSL: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- RHSA-2026:67551 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:62790 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:62563 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:62562 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:59635 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:59641 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:55543 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:42825 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
References
- OpenSSL Advisory vendor-advisory
- 4.0.1 git commit patch
- 3.6.3 git commit patch