CVE-2026-39998

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.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://lists.apache.org/thread/vgkvy396010d7g6m0jrn4d3hjf2svlvv	Vendor Advisory Mailing List
http://www.openwall.com/lists/oss-security/2026/06/19/4	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:apache:apisix:*:*:*:*:*:*:*:*

History

23 Jun 2026, 14:57

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 8.8
CPE		cpe:2.3:a:apache:apisix::::::::
First Time		Apache apisix Apache
References	~~() https://lists.apache.org/thread/vgkvy396010d7g6m0jrn4d3hjf2svlvv -~~	() https://lists.apache.org/thread/vgkvy396010d7g6m0jrn4d3hjf2svlvv - Vendor Advisory, Mailing List
References	~~() http://www.openwall.com/lists/oss-security/2026/06/19/4 -~~	() http://www.openwall.com/lists/oss-security/2026/06/19/4 - Third Party Advisory

19 Jun 2026, 17:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-19 14:16

Updated : 2026-06-23 14:57

NVD link : CVE-2026-39998

Mitre link : CVE-2026-39998

CVE.ORG link : CVE-2026-39998

JSON object : View

Products Affected

apache

apisix

CWE

CWE-20

Improper Input Validation

{"id": "CVE-2026-39998", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-39998", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-22T16:16:18.557213Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "security@apache.org", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 5.8, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "subIntegrityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "security@apache.org", "affectedData": [{"vendor": "Apache Software Foundation", "product": "Apache APISIX", "versions": [{"status": "affected", "version": "2.12.0", "versionType": "semver", "lessThanOrEqual": "3.16.0"}], "defaultStatus": "unaffected"}]}], "published": "2026-06-19T14:16:21.823", "references": [{"url": "https://lists.apache.org/thread/vgkvy396010d7g6m0jrn4d3hjf2svlvv", "tags": ["Vendor Advisory", "Mailing List"], "source": "security@apache.org"}, {"url": "http://www.openwall.com/lists/oss-security/2026/06/19/4", "tags": ["Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security@apache.org", "description": [{"lang": "en", "value": "CWE-20"}]}], "descriptions": [{"lang": "en", "value": "Improper Input Validation vulnerability in Apache APISIX.\n\nThe attacker can take advantage of certain configuration in forward-auth plugin to spoof identity headers.\nThis issue affects Apache APISIX: from 2.12.0 through 3.16.0.\n\nUsers are recommended to upgrade to version 3.17.0, which fixes the issue."}], "lastModified": "2026-06-23T14:57:13.603", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:apache:apisix:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5594B6F8-4C43-4244-92CC-04C8BA3A9FA1", "versionEndExcluding": "3.17.0", "versionStartIncluding": "2.12.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@apache.org"}