CVE-2026-62971— OWASP CRS: XML Attribute Value Bypass

Quick assessment

Affected

coreruleset coreruleset

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

OWASP 核心规则集（CRS）是一套适用于兼容 Web 应用防火墙的通用攻击检测规则。在版本 3.3.10、4.25.1 和 4.28.0 之前，CRS 中属于以下规则族（921 协议攻击、930 本地文件包含 LFI、931 远程文件包含 RFI、932 远程代码执行 RCE、933 PHP 相关、934 通用、941 XSS、942 SQL 注入 SQLi 以及 943 会话固定）的规则，均通过 XPath 表达式检查 XML 请求体。该表达式仅匹配元素的文本节点，无法匹配 XML 属性值。因此，攻击者若将

CVSS 7.2 · High Updated Nov 12, 2026

Possible ATT&CK Techniques 2 AI

T1059.007 · JavaScript T1190 · Exploit Public-Facing Application

Affected Version Matrix 3

Vendor	Product	Version Range	Status
coreruleset	coreruleset	`< 3.3.10`	affected
		`< 4.25.1`	affected
		`< 4.28.0`	affected

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Vulnerability Information

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Vulnerability Title

OWASP CRS: XML Attribute Value Bypass

Source: CVE Program / CVE List V5

Vulnerability Description

The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls. Prior to versions 3.3.10, 4.25.1, and 4.28.0, CRS rules in the 921 (protocol-attack), 930 (LFI), 931 (RFI), 932 (RCE), 933 (PHP), 934 (generic), 941 (XSS), 942 (SQLi), and 943 (session-fixation) families inspect XML request bodies via the XPath expression XML:/*. That expression matches only element text nodes — it does not match XML attribute values. As a result, an attacker who places an attack payload inside an XML attribute (e.g. <a href="javascript:alert(1)=window.name"></a> or <a value="' OR 1=1 --"></a>) bypasses CRS detection entirely. This is verified empirically against a local CRS test instance and against the public CRS sandbox. The bypass affects approximately 159 rules across 9 rule files and applies at every paranoia level (PL1 through PL4), since the variable list is more or less shared across PLs. The 944 (Java) family is the only one that correctly includes XML://@* in addition to XML:/* and is therefore unaffected. This issue has been patched in versions 3.3.10, 4.25.1, and 4.28.0.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

对特殊元素的转义处理不恰当

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
coreruleset	coreruleset	< 3.3.10	-

II. Public POCs for CVE-2026-62971

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-62971

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Other References for CVE-2026-62971 (5)

https://github.com/owasp-modsecurity/ModSecurity/issues/3591 x_refsource_MISC
https://github.com/coreruleset/coreruleset/security/advisories/GHSA-6jp8-c2w2-x7wr x_refsource_CONFIRM
https://github.com/coreruleset/coreruleset/commit/852036b6af5e81d60d7234f69137d47f4ecb89dc x_refsource_MISC
https://github.com/coreruleset/coreruleset/commit/635cecf8f81908f02a687db4b5b13a55c3e3b9ed x_refsource_MISC
https://github.com/coreruleset/coreruleset/commit/275d7616f1ceb6f1024c3bfbeb1f4ae2ae9ad010 x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-62971

IV. Related Vulnerabilities

Same product: coreruleset

Same vendor: coreruleset

Same weakness: CWE-138