CVE-2026-31908
Apache Apisix 2.12.0 – 3.16.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NSummary
CVE-2026-31908 is a critical-severity Special Element Injection (CWE-75) vulnerability in Apache Apisix. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 42th 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) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-31908 is a header injection vulnerability in Apache APISIX, affecting versions from 2.12.0 through 3.15.0. The issue arises in the forward-auth plugin under certain configurations, allowing an attacker to inject malicious headers. It has a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N) and is associated with CWE-75.
Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity. By leveraging the forward-auth plugin's configuration, they can inject malicious headers, potentially leading to high impacts on confidentiality and integrity, such as unauthorized data access or modification.
Apache advisories recommend upgrading to version 3.16.0, which resolves the issue. Further details are available in the Apache mailing list announcement at https://lists.apache.org/thread/sob643s5lztov7x579j8o0c444t36n6b and the OSS-Security mailing list at http://www.openwall.com/lists/oss-security/2026/04/14/3.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-22225
Vulnerability Data
Header injection vulnerability in Apache APISIX. The attacker can take advantage of certain configuration in forward-auth plugin to inject malicious headers. This issue affects Apache APISIX: from 2.12.0 through 3.15.0. Users are recommended to upgrade to version 3.16.0, which fixes…
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the issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Input validation directly stops special-element injection by rejecting or sanitizing untrusted data before it reaches a different control plane.
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.
Secure SDLC practices directly require input sanitization to block special-element injection.
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.
Security testing catches injection vulnerabilities but does not itself implement the sanitization fix.
Logging can record injection attempts for detection but does not prevent the weakness.
Secure development life cycle mandates input validation and sanitization practices that directly prevent special-element injection.
Application security requirements explicitly call for controls against injection flaws including special-element handling.
Secure architecture principles reduce injection surfaces but do not prescribe the actual sanitization logic.
Secure coding standards require rigorous input sanitization, directly eliminating CWE-75.