Apache Syncope: JWT subject spoofing

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-87785
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-14 11:17:05 UTC
Updated2026-09-14 20:58:48 UTC
DescriptionAuthentication bypass by spoofing vulnerability in Apache Syncope. When the configured JWKS settings for internal JWT authentication are disclosed (at least protocol and key), an attacker can spoof another user's privileges after completing a successful authentication and obtaining a valid JWT. This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 through 4.0.7, from 4.1.0-M0 through 4.1.2. Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.

Risk And Classification

Primary CVSS: v3.1 9.1 CRITICAL from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS: 0.005120000 probability, percentile 0.421910000 (date 2026-09-15)

Problem Types: CWE-290 | CWE-290 CWE-290 Authentication bypass by spoofing

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary9.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Syncope affected 3.0.0-M0 3.0.16 semver Not specified
CNA Apache Software Foundation Apache Syncope affected 4.0.0-M0 4.0.7 semver Not specified
CNA Apache Software Foundation Apache Syncope affected 4.1.0-M0 4.1.2 semver Not specified

References

ReferenceSourceLinkTags
lists.apache.org/thread/3t3om8mny7ng52q053pdzpmtdtosnqoo [email protected] lists.apache.org
www.openwall.com/lists/oss-security/2026/09/14/24 af854a3a-2127-422b-91ae-364da2661108 www.openwall.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Alon Galili (en)

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