SOAP HTTP Client Heap Buffer Overflow

Publication date: 2026-09-25

Last updated on: 2026-09-25

Assigner: PHP Group

Description

The SOAP HTTP client guards its response buffer growth with a check that relies on signed integer overflow, which is undefined behaviour and is not guaranteed to trigger. When the check is optimised away, a malicious SOAP server can make the client allocate a buffer far smaller than the data it then writes into it, producing a heap buffer overflow.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-25

Last Modified

2026-09-25

Generated

2026-09-26

AI Q&A

2026-09-26

EPSS Evaluated

N/A

NVD

CVE-2025-14181

Affected Vendors & Products

Vendor	Product	Version / Range
php	soap	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-190	The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Attack-Flow Graph

Executive Summary

This vulnerability involves a SOAP HTTP client that uses a check relying on signed integer overflow to control response buffer growth. Since signed integer overflow is undefined behavior, compilers may optimize away this check. A malicious SOAP server could exploit this by making the client allocate a buffer much smaller than the actual data size, leading to a heap buffer overflow when writing data.

Impact Analysis

This vulnerability could allow an attacker to execute arbitrary code or cause a denial of service by overflowing the heap buffer. If exploited, it may lead to system crashes, data corruption, or unauthorized access to sensitive information.

Mitigation Strategies

Update PHP to the latest patched version to address the SOAP HTTP client buffer overflow issue. Monitor vendor advisories for PHP SOAP extensions and apply security patches promptly.

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