CVE-2026-91769: TLS Hostname Verification Falls Back to CN After SAN Mismatch
Noroxi assessment
Priority: Monitor (action score 17/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.15% (FIRST EPSS).
- Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: PHP Group PHP 8.2.34, 8.3.35, 8.4.26; azl3 php 8.3.33-1 on Azure Linux 3.0 8.3.35-1.
Low priority for now. Upgrade to PHP Group PHP 8.2.34, 8.3.35, 8.4.26; azl3 php 8.3.33-1 on Azure Linux 3.0 8.3.35-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another.
- Published
- Sep 25, 2026
- Updated
- Oct 23, 2026
- EPSS
- 0.1% · 5th percentile
- CWE
- CWE-297
Report tools
Action score
17
Monitor
Low priority for now.
- CVSS
- 17 / 40 · 4.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · php
- 4.3
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| php | php | cpe:2.3:a:php:php |
Using php? Add it to your stack and be the first to know about CVEs like this one. (PHP)
Check your site's encryption
This vulnerability is about certificate validation or weak cryptography. The free SSL checker tests your certificate, enabled TLS versions and weak ciphers.
Run the SSL checkAffected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- php php8.2.0 and later · before 8.2.34
- php php8.3.0 and later · before 8.3.35
- php php8.4.0 and later · before 8.4.26
- php php8.5.0 and later · before 8.5.11
Versions reported by the vendor
Affected version ranges reported by the assigning authority (php). Independent of NVD's CPE analysis and usually ahead of it.
PHP Group PHP
- 8.2.* and later · before 8.2.34affected · semver
- 8.3.* and later · before 8.3.35affected · semver
- 8.4.* and later · before 8.4.26affected · semver
- 8.5.* and later · before 8.5.11affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | apcu-panel | before 5.1.18-1.module_el8.6.0+2750+78feabcb | 5.1.18-1.module_el8.6.0+2750+78feabcb |
| AlmaLinux:8 | libzip | before 1.6.1-1.module_el8.6.0+2750+78feabcb | 1.6.1-1.module_el8.6.0+2750+78feabcb |
| AlmaLinux:8 | libzip | before 1.6.1-1.module_el8.10.0+3935+28808425 | 1.6.1-1.module_el8.10.0+3935+28808425 |
| AlmaLinux:8 | libzip | before 1.6.1-1.module_el8.6.0+3239+bedf0508 | 1.6.1-1.module_el8.6.0+3239+bedf0508 |
| AlmaLinux:8 | libzip-devel | before 1.6.1-1.module_el8.10.0+3935+28808425 | 1.6.1-1.module_el8.10.0+3935+28808425 |
| AlmaLinux:8 | libzip-devel | before 1.6.1-1.module_el8.6.0+3239+bedf0508 | 1.6.1-1.module_el8.6.0+3239+bedf0508 |
| AlmaLinux:8 | libzip-devel | before 1.6.1-1.module_el8.6.0+2750+78feabcb | 1.6.1-1.module_el8.6.0+2750+78feabcb |
| AlmaLinux:8 | libzip-tools | before 1.6.1-1.module_el8.10.0+3935+28808425 | 1.6.1-1.module_el8.10.0+3935+28808425 |
| AlmaLinux:8 | libzip-tools | before 1.6.1-1.module_el8.6.0+3239+bedf0508 | 1.6.1-1.module_el8.6.0+3239+bedf0508 |
| AlmaLinux:8 | php | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-bcmath | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-cli | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-common | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-dba | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-dbg | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-devel | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-embedded | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-enchant | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-ffi | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-fpm | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-gd | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-gmp | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-intl | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
| AlmaLinux:8 | php-json | before 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb |
+96
Same product
php: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-4577Argument Injection in PHP-CGIKEV99Now
- CVE-2019-11043Underflow in PHP-FPM can lead to RCEKEV99Now
- CVE-2012-1823sapi/cgi/cgi_main.c in PHP before 5.3.12 and 5.4.x before 5.4.2, when configured as a CGI script (aka php-cgi), does not properly handle queKEV99Now
Published before and after this one in the same product
- ← EarlierCVE-2026-91766Sep 25, 2026 · Cross-origin credential leak in HTTP stream wrapper redirects23Monitor
- ← EarlierCVE-2026-91767Sep 25, 2026 · Heap-buffer-overflow in php_openssl_matches_wildcard_name on crafted server cert wildcard CN26Monitor
- Later →CVE-2026-91768Sep 25, 2026 · IPv6 ACL bypass in FastCGI listen.allowed_clients due to partial address comparison (memcmp 12 bytes)26Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| PHP Group PHP | 8.2.34 | Vendor (CNA) |
| PHP Group PHP | 8.3.35 | Vendor (CNA) |
| PHP Group PHP | 8.4.26 | Vendor (CNA) |
| PHP Group PHP | 8.5.11 | Vendor (CNA) |
| azl3 php 8.3.33-1 on Azure Linux 3.0 | 8.3.35-1 · Release Notes | Microsoft (MSRC) |
| almalinux:apcu-panel | 5.1.18-1.module_el8.6.0+2750+78feabcb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libzip | 1.6.1-1.module_el8.6.0+2750+78feabcb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libzip-devel | 1.6.1-1.module_el8.10.0+3935+28808425 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:libzip-tools | 1.6.1-1.module_el8.10.0+3935+28808425 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-bcmath | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-cli | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-common | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-dba | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-dbg | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-devel | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| almalinux:php-embedded | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb · AlmaLinux:8 | Package registry (OSV) |
| alpine:php82 | 8.2.35-r0 · Alpine:v3.22 | Package registry (OSV) |
| alpine:php83 | 8.3.36-r0 · Alpine:v3.22 | Package registry (OSV) |
| alpine:php84 | 8.4.27-r0 · Alpine:v3.22 | Package registry (OSV) |
| alpine:php85 | 8.5.12-r0 · Alpine:v3.23 | Package registry (OSV) |
| debian:php8.2 | 8.2.34-1~deb12u1 · Debian:12 | Package registry (OSV) |
| debian:php8.4 | 8.4.26-1~deb13u1 · Debian:13 | Package registry (OSV) |
| opensuse:apache2-mod_php8 | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8 | 8.5.11-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:php8-embed | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8-fastcgi | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8-fpm | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| opensuse:php8-test | 8.4.26-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| red hat:php | 0:8.5.11-2.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
+35
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Cantina (https://www.cantina.security/)reporter
- David Korczynskireporter
- Jakub Zelenkaremediation developer
- Arnaud Le Blancremediation reviewer
- Alexandre Dauboisremediation reviewer
- @benzdeus (GitHub)reporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Adjacent
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-297 · Improper Validation of Certificate with Host MismatchCVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
- SSVC exploitation— → none
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