Unauthenticated process crash via unbounded SOAP recursion
Published Sep 25, 2026 · Updated Sep 25, 2026
Uncontrolled recursion in PHP ext-soap before 8.2.34, 8.3.35, 8.4.26, and 8.5.11 allows remote attackers to crash PHP processes. cleanup_xml_node() descends through every attacker-controlled XML child without a depth limit, while related decoders also recurse without bounds. Any unauthenticated request reaching a SoapServer endpoint can exhaust a worker stack; repeated requests can take the endpoint offline without granting code execution.
Summary
What happened
Uncontrolled recursion in PHP ext-soap before 8.2.34, 8.3.35, 8.4.26, and 8.5.11 allows remote attackers to crash PHP processes. cleanup_xml_node() descends through every attacker-controlled XML child without a depth limit, while related decoders also recurse without bounds. Any unauthenticated request reaching a SoapServer endpoint can exhaust a worker stack; repeated requests can take the endpoint offline without granting code execution.
The record
- CVE
- CVE-2026-91765
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- PHP Development Team
- Product
- PHP
- Classifications
- T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=8.2.* <8.2.34
- Affected versionversion=8.3.* <8.3.35
- Affected versionversion=8.4.* <8.4.26
- Affected versionversion=8.5.* <8.5.11
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
- Upstream nested SOAP element proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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