# CVE-2026-31908: Header injection vulnerability in Apache APISIX. The attacker can take advantage of certain configuration in…

Source: https://junglewise.ai/threats/cve-2026-31908-header-injection-vulnerability-in-apache-apisix-the-attacker-can  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-14  
License: CC BY 4.0 with a link back

CVE-2026-31908 · Severity: critical · CVSS 9.1 · Published 2026-04-14

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 the issue.

Technologies: [Apache APISIX](https://junglewise.ai/threats/technologies/apisix). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache).

## Quick answers

**Is CVE-2026-31908 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-31908 being exploited in the wild.

**How severe is CVE-2026-31908?** Critical severity, with a CVSS score of 9.1, published 14 April 2026.

**Which products and versions are affected?** Apache APISIX. The advisory does not name versions.

**Is there a fix for CVE-2026-31908?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-31908?** Check whether you run Apache APISIX. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Apache APISIX

## Related threats

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- [Apache APISIX authorization bypass via non-canonical URL paths](https://junglewise.ai/threats/cve-2026-94269-use-of-non-canonical-url-paths-for-authorization-decisions)
- [Apache APISIX batch-requests plugin uncontrolled resource allocation](https://junglewise.ai/threats/cve-2026-94250-allocation-of-resources-without-limits-or-throttling)
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- [Apache APISIX cryptographic signature verification bypass in saml-auth](https://junglewise.ai/threats/cve-2026-94212-improper-verification-of-cryptographic-signature-vulnerability-in)