PHP up to 8.2.33/8.3.34/8.4.25/8.5.10 OpenSSL ext/openssl/xp_ssl.c php_openssl_matches_wildcard_name length heap-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.8$5k-$25k0.00+

Summaryinfo

A vulnerability was found in PHP up to 8.2.33/8.3.34/8.4.25/8.5.10 and classified as critical. Impacted is the function php_openssl_matches_wildcard_name of the file ext/openssl/xp_ssl.c of the component OpenSSL. Executing a manipulation of the argument length can lead to heap-based overflow. This vulnerability is registered as CVE-2026-91767. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in PHP up to 8.2.33/8.3.34/8.4.25/8.5.10. It has been declared as critical. This vulnerability affects the function php_openssl_matches_wildcard_name of the file ext/openssl/xp_ssl.c of the component OpenSSL. The manipulation of the argument length with an unknown input leads to a heap-based overflow vulnerability. The CWE definition for the vulnerability is CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

php_openssl_matches_wildcard_name() in ext/openssl/xp_ssl.c underflows the length argument passed to memchr() when a TLS server certificate presents a wildcard name whose literal characters are together longer than the hostname being verified. A malicious server presenting such a certificate makes the PHP client read up to SIZE_MAX bytes past the end of a heap allocation. The path is reachable from any default client stream, because verify_peer_name is enabled by default.

The advisory is available at github.com. This vulnerability was named CVE-2026-91767 since 09/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 8.2.34, 8.3.35, 8.4.26 or 8.5.11 eliminates this vulnerability.

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Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (php): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: PHP 8.2.34/8.3.35/8.4.26/8.5.11

Timelineinfo

09/15/2026 CVE reserved
09/25/2026 +10 days Advisory disclosed
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Product: php.org

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-91767 (🔒)
GCVE (CVE): GCVE-0-2026-91767
GCVE (VulDB): GCVE-100-410470

Entryinfo

Created: 09/25/2026 23:14
Changes: 09/25/2026 23:14 (67)
Complete: 🔍
Cache ID: 216::103

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