Apache Struts: Improper Neutralization of Special Elements used in an Expression Language Statement
CVE-2026-104711 is a critical-severity improper neutralization of special elements used in an expression language statement vulnerability in Apache Struts from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Apache Struts versions: 2.0.0 through 2.3.37; 2.5.0 through 2.5.33; 6.0.0 through 6.11.0, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.65% chance of exploitation within 30 days, higher than 77% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Struts to 6.12.0 or 7.4.0, whichever matches your release line, or a later version.
- Read the advisory on cwiki.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache Struts | 2.0.0 through 2.3.37; 2.5.0 through 2.5.33; 6.0.0 through 6.11.0; 7.0.0 through 7.3.0 | Not stated |
| Apache | Struts | 2.0.0 through 2.3.37; 2.5.0 through 2.5.33; 6.0.0 up to, but not including, 6.12.0; 7.0.0 up to, but not including, 7.4.0 | 6.12.0, 7.4.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
Improper neutralization of special elements used in an expression language statement ('Expression Language Injection') vulnerability in Apache Struts. If the application is configured to use the legacy RESTful action mapper, a crafted request can inject an OGNL expression that may lead to remote code execution. Struts 7 is affected only when the OGNL allowlist is disabled; it is enabled by default. Applications using the default action mapper, the restful2 mapper, or the Struts REST plugin are not affected. This issue affects Apache Struts: from 2.0.0 through 2.3.37, from 2.5.0 through 2.5.33, from 6.0.0 through 6.11.0, from 7.0.0 through 7.3.0. Users are recommended to upgrade to version 6.12.0 or 7.4.0, which fixes the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an Expression Language Statement
The product constructs all or part of an expression language (EL) statement in a framework such as a Java Server Page (JSP) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended EL statement before it is executed.
How developers prevent this class of flaw
- Avoid adding user-controlled data into an expression interpreter when possible.
- If user-controlled data must be added to an expression interpreter, one or more of the following should be performed: Validate that the user input will not evaluate as an expression Encode the user input in a way that ensures it is not evaluated as an expression
- The framework or tooling might allow the developer to disable or deactivate the processing of EL expressions, such as setting the isELIgnored attribute for a JSP page to true.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- openwall.com/lists/oss-security/2026/10/05/10Mailing List, Third Party Advisory
Other vulnerabilities in Apache Struts
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
Recent Improper Neutralization of Special Elements used in an Expression Language Statement vulnerabilities
- 9.1 Critical severity
- 7.1 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.1 High severity
- 8.1 High severity
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