CVE-2026-39998

Apache APISIX: Identity Injection via forward-auth Plugin Missing Header Cleanup

HIGH
8.8
CVSS Score
Published: June 19, 2026 at 01:04 PM UTC
Updated: October 26, 2026 at 11:10 AM UTC
1 product affected across 1 vendorApisix

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Severity
HIGH8.8
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

Improper Input Validation vulnerability in Apache APISIX. The attacker can take advantage of certain configuration in forward-auth plugin to spoof identity headers. This issue affects Apache APISIX: from 2.12.0 through 3.16.0. Users are recommended to upgrade to version 3.17.0, which fixes the issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.12.0 ≤ v < 3.17.02.12.0
Affected range stops below 3.17.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Vendor AdvisoryMailing List
Source: cverecord
https://lists.apache.org/thread/vgkvy396010d7g6m0jrn4d3hjf2svlvv
Third Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/06/19/4

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20

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