Null byte termination in hostnames
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 2 fixed, 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-918 and the CVSS impact.
Summary
In PHP versions:8.1.* before 8.1.33, 8.2.* before 8.2.29, 8.3.* before 8.3.23, 8.4.* before 8.4.10 some functions like fsockopen() lack validation that the hostname supplied does not contain null characters. This may lead to other functions like parse_url() treat the hostname in different way, thus opening way to security problems if the user code implements access checks before access using such functions.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| PHP Group | PHP | before 8.1.33; before 8.2.29; before 8.3.23; before 8.4.10 | 8.1.33, 8.2.29, 8.3.23, 8.4.10 | Patch available | CNA |
- PHP VendorPHP Group Affected before 8.1.33; before 8.2.29; before 8.3.23; before 8.4.10 Fixed in 8.1.33, 8.2.29, 8.3.23, 8.4.10 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:php:php:*:*:*:*:*:*:*:* | 8.1.0 to before 8.1.33; 8.2.0 to before 8.2.29; 8.3.0 to before 8.3.23; 8.4.0 to before 8.4.10 | Vulnerable | PHP |
- cpe:2.3:a:php:php:*:*:*:*:*:*:*:* Versions 8.1.0 to before 8.1.33; 8.2.0 to before 8.2.29; 8.3.0 to before 8.3.23; 8.4.0 to before 8.4.10 Vulnerable ·PHP
Remediation
- Fix · CNA PHP (PHP Group) Fixed in 8.1.33, 8.2.29, 8.3.23, 8.4.10
Red Hat 4 advisories
- RHSA-2026:2470 Released 2026-02-10 · Red Hat rating Moderatephp:7.4 security update
- Red Hat Enterprise Linux AppStream (v. 8) apcu-panel-5.1.18-1.module+el8.10.0+22485+a3539972.noarch::php:7.4, libzip-1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4, libzip-1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4 +47
- RHSA-2026:1409 Released 2026-01-27 · Red Hat rating Importantphp:8.2 security update
- Red Hat Enterprise Linux AppStream (v. 9) apcu-panel-5.1.23-1.module+el9.4.0+20748+b46899d2.noarch::php:8.2, php-8.2.30-1.module+el9.7.0+23849+7b831f17.aarch64::php:8.2, php-8.2.30-1.module+el9.7.0+23849+7b831f17.ppc64le::php:8.2 +47
- RHSA-2026:1412 Released 2026-01-27 · Red Hat rating Importantphp:8.2 security update
- Red Hat Enterprise Linux AppStream (v. 8) apcu-panel-5.1.23-1.module+el8.10.0+20770+a5eca186.noarch::php:8.2, libzip-1.7.3-1.module+el8.10.0+20770+a5eca186.aarch64::php:8.2, libzip-1.7.3-1.module+el8.10.0+20770+a5eca186.ppc64le::php:8.2 +47
Show 1 more Red Hat advisories
- RHSA-2025:23309 Released 2025-12-18 · Red Hat rating Moderatephp:8.3 security update
- Red Hat Enterprise Linux AppStream (v. 9) apcu-panel-5.1.23-1.module+el9.6.0+22647+1741ae35.noarch::php:8.3, php-8.3.26-1.module+el9.7.0+23549+c13c2ce3.aarch64::php:8.3, php-8.3.26-1.module+el9.7.0+23549+c13c2ce3.ppc64le::php:8.3 +47
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
PHP 8.1.33, 8.2.29 and 2 more versions
3 records Highest priority Priority MEDIUM 2 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2025-05892 NULL Pointer Dereference in PHP SOAP Extension via Large XML Namespace PrefixPriority MEDIUM 60
- TI-2025-01493 pgsql extension does not check for errors during escapingPriority LOW 35
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:1412, RHSA-2026:2470 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:23309, RHSA-2026:1409 |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-1220
- 2026-10-23 EPSS moved to the 50th–90th percentile
References
More PHP Group vulnerabilities
- TI-2024-04260 Argument Injection in PHP-CGI KEVCVSS 3.1CRITICAL 9.8
- TI-2026-78794 PHP remote code execution via stale global state KEVCVSS 4.0CRITICAL 9.2
- TI-2026-78793 Out-of-memory handling flaw in PHP allows remote code execution KEVCVSS 4.0CRITICAL 9.2
- TI-2024-01743 Command injection via array-ish $command parameter of proc_open() CVSS 3.1CRITICAL 9.4
- TI-2022-13555 PDO::quote() may return unquoted string CVSS 3.1CRITICAL 9.1
- TI-2024-10408 Reference counting in php_request_shutdown causes Use-After-Free CVSS 4.0CRITICAL 9.2
Sources
- CVE-2025-1220 · CVE Program
- CVE-2025-1220 · NVD
- FIRST EPSS
- CVE-2025-1220 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences