Cyber Resilience

CVE-2026-7263

DoS in Php 8.4.0 – 8.4.21

DoS
Published
10 May 2026
Modified
24 July 2026
Patch / advisory
View advisory
CVSS Score v4 6.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:Amber
EPSS Score 0.0035 28th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-7263 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Php Php. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 28th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-2 (Flaw Remediation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, DOMNode::C14N() method may process the XML data incorrectly, causing a circular linked list in the data structure representing the XML document. This may cause subsequent processing of the XML document…

more

to enter infinite loop, causing denial of service in the processing application.

CWE(s)
CWE-404CWE-835

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

Vulnerability in PHP DOM C14N() processing enables direct exploitation to trigger infinite loop and endpoint DoS.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1499.004 Application or System Exploitation Impactconfidence: HIGH
Vulnerability in DOMNode::C14N() creates circular list leading to infinite loop and application DoS.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-7262Same product: Php Php
CVE-2025-6491Same product: Php Php
CVE-2026-7568Same product: Php Php
CVE-2026-7258Same product: Php Php
CVE-2026-7259Same product: Php Php
CVE-2024-2757Same product: Php Php
CVE-2025-1217Same product: Php Php
CVE-2025-1735Same product: Php Php
CVE-2026-6722Same product: Php Php
CVE-2025-1219Same product: Php Php

Affected Assets

php
php
8.4.0 — 8.4.21 · 8.5.0 — 8.5.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • SI-10 Information Input Validation
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Directly requires applying the vendor patches that fix the DOMNode::C14N circular-list flaw in PHP 8.4/8.5.

SI-10 Information Input Validation good match
prevent

Enforces validation of XML input before C14N processing, blocking malformed documents that trigger the infinite loop.

SI-4 System Monitoring partial match
detect

Monitors for anomalous CPU or processing time that would result from the infinite loop caused by the circular XML structure.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards for correct resource allocation and release.

DE.CM-09 partial match
prevents

Runtime monitoring can detect resource exhaustion caused by improper shutdown or release.

ID.AM-08 partial match
prevents

Lifecycle management of assets can encompass proper resource release at end-of-life or shutdown.

ID.RA-01 partial match
prevents

Static analysis and vuln scanning during asset assessment can detect unreachable loop exits.

PR.IR-04 partial match
prevents

Capacity management helps surface leaks from unreleased resources but does not prevent the coding flaw.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing can uncover infinite-loop conditions before release.

A.5.37 Documented operating procedures partial match
prevents

Including restart, recovery and media-handling instructions reduces the likelihood that resources or sensitive data will be left in an exposed or improperly released state after a failure.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that can detect and prevent infinite-loop defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify loop-termination rules, indirectly reducing the weakness.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address loop termination and prevent infinite loops.

A.8.27 Secure system architecture and engineering principles none match
none

Secure architecture principles encourage designs that avoid unreachable exit conditions.

References