Is CVE-2026-91769 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-91769 being exploited in the wild.

How severe is CVE-2026-91769?

Medium severity, with a CVSS score of 4.3, published 25 September 2026.

Which products and versions are affected?

Php <8.2.34, <8.3.35, <8.4.26, <8.5.11.

Is there a fix for CVE-2026-91769?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-91769 attacked?

It is attacked from the adjacent network.

Am I affected by CVE-2026-91769?

Check whether you run Php at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-91769: PHP OpenSSL stream peer verification certificate validation bypass

Q: Which products and versions are affected?

Php <8.2.34, <8.3.35, <8.4.26, <8.5.11.

Q: Is there a fix for CVE-2026-91769?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

Q: How is CVE-2026-91769 attacked?

It is attacked from the adjacent network.

Q: Am I affected by CVE-2026-91769?

Check whether you run Php at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-91769 · Severity: medium · CVSS 4.3 · Published 2026-09-25

PHP's OpenSSL stream connection handler incorrectly accepts certificates with mismatched hostnames by falling back to the certificate's Common Name even when a Subject Alternative Name (SAN) is present. An attacker with a certificate for one hostname can impersonate a different hostname to PHP applications making HTTPS or TLS connections, potentially exposing sensitive data transmitted to the wrong server.

Technologies: Php. Vendors: PHP.

Quick answers

Is CVE-2026-91769 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-91769 being exploited in the wild.
How severe is CVE-2026-91769?: Medium severity, with a CVSS score of 4.3, published 25 September 2026.
Which products and versions are affected?: Php <8.2.34, <8.3.35, <8.4.26, <8.5.11.
Is there a fix for CVE-2026-91769?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-91769 attacked?: It is attacked from the adjacent network.
Am I affected by CVE-2026-91769?: Check whether you run Php at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The php_openssl_apply_peer_verification_policy() function fails to follow RFC 6125, which requires suppressing Common Name matching once a certificate presents service identity via SAN. A certificate with CN=victim.test and SAN=attacker.test is accepted when connecting to victim.test, indicating the fallback to CN occurs despite SAN presence. The vulnerability affects all default peer name verification in streams including file_get_contents(), fopen(), and stream_socket_client() over https:// and tls://, and is fixed in PHP 8.2.34, 8.3.35, 8.4.26, and 8.5.11.

Affected products

PHP PHP <8.2.34, <8.3.35, <8.4.26, <8.5.11

Timeline

2026-09-25: disclosed

References

https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx

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