Improper verification of cryptographic signature vulnerability in Apache Syncope. (CVE-2026-87802)
Apache Syncope contains a critical vulnerability involving improper verification of cryptographic signatures when SRA is configured for OAuth 2.0 without a JWKS URI set. This flaw allows attackers to forge arbitrary JWTs to impersonate any user and gain full access to proxied services. The issue affects versions from 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2. Upgrading to versions 4.0.8 or 4.1.3 resolves the vulnerability.
AI Analysis
Technical Summary
CVE-2026-87802 describes an improper verification of cryptographic signatures in Apache Syncope's SRA OAuth 2.0 configuration when no JWKS set URI is assigned. This allows attackers to forge JWT tokens to impersonate any user identity and permissions, thereby gaining unauthorized full access to services proxied by the SRA component. The vulnerability affects Apache Syncope versions 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2. The issue is fixed in versions 4.0.8 and 4.1.3.
Potential Impact
Successful exploitation enables an unauthenticated attacker to forge JWT tokens, impersonate any user, and gain full access to services proxied by the Syncope SRA. This leads to complete compromise of user identities and permissions within affected environments. The CVSS v3.1 score is 9.1 (critical), reflecting high impact on confidentiality and integrity without requiring privileges or user interaction.
Mitigation Recommendations
Users should upgrade Apache Syncope to version 4.0.8 or 4.1.3, which contain fixes for this vulnerability. No other mitigations are indicated. Patch status is confirmed by the vendor advisory information.
Improper verification of cryptographic signature vulnerability in Apache Syncope. (CVE-2026-87802)
Description
Apache Syncope contains a critical vulnerability involving improper verification of cryptographic signatures when SRA is configured for OAuth 2.0 without a JWKS URI set. This flaw allows attackers to forge arbitrary JWTs to impersonate any user and gain full access to proxied services. The issue affects versions from 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2. Upgrading to versions 4.0.8 or 4.1.3 resolves the vulnerability.
CVSS v3.1
Score 9.1critical
Affected software
pkg:maven/org.apache.syncope/syncope-coreRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-87802 describes an improper verification of cryptographic signatures in Apache Syncope's SRA OAuth 2.0 configuration when no JWKS set URI is assigned. This allows attackers to forge JWT tokens to impersonate any user identity and permissions, thereby gaining unauthorized full access to services proxied by the SRA component. The vulnerability affects Apache Syncope versions 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2. The issue is fixed in versions 4.0.8 and 4.1.3.
Potential Impact
Successful exploitation enables an unauthenticated attacker to forge JWT tokens, impersonate any user, and gain full access to services proxied by the Syncope SRA. This leads to complete compromise of user identities and permissions within affected environments. The CVSS v3.1 score is 9.1 (critical), reflecting high impact on confidentiality and integrity without requiring privileges or user interaction.
Mitigation Recommendations
Users should upgrade Apache Syncope to version 4.0.8 or 4.1.3, which contain fixes for this vulnerability. No other mitigations are indicated. Patch status is confirmed by the vendor advisory information.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-mg52-7466-j5f7
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-87802"]
- Database Specific Severity
- CRITICAL
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aa8a1d055bf5e2cf5f3e933
Added to database: 09/15/2026, 01:39:28 UTC
Last enriched: 09/15/2026, 02:02:34 UTC
Last updated: 09/15/2026, 06:01:23 UTC
Views: 6
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.