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TI-2026-47647 Aliases CVE-2026-67351

Serendipity < 2.6.1 Authentication Bypass via Username Collision

Priority HIGH 73CWE-304Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Serendipity before 2.6.1 contains an authentication context confusion vulnerability where password validation and session loading operate independently without ensuring both use the same user record. An authenticated Editor can create a username collision with an Administrator account and obtain administrative privileges by logging in with their own password while the session loads the Administrator's account data.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00555 46th percentileScored 2026-11-07
Fix Fixed Serendipity (s9y): 2.6.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
s9ySerendipitybefore 2.6.12.6.1Patch availableCNA
  • Serendipity Vendors9y Affected before 2.6.1 Fixed in 2.6.1 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:s9y:serendipity:*:*:*:*:*:*:*:*——s9y
  • cpe:2.3:a:s9y:serendipity:*:*:*:*:*:*:*:* Versions — — ·s9y

Remediation

  • Fix · CNA Serendipity (s9y) Fixed in 2.6.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-67351

References

Advisory 1

  • TI-2023-30216 Serendipity 2.4.0 Authenticated Remote Code Execution via File Upload CVSS 4.0HIGH 8.7
  • TI-2024-38379 Serendipity 2.5.0 Remote Code Execution via Authenticated Media Upload CVSS 4.0HIGH 8.6
  • TI-2026-28827 Serendipity: Host Header Injection leads to SMTP header injection via unvalidated HTTP_HOST CVSS 3.1HIGH 7.2
  • TI-2026-28819 Serendipity: Host Header Injection enables authentication cookie scoping to an attacker-controlled domain CVSS 3.1MEDIUM 6.9
  • TI-2026-51712 Serendipity 2.3.5 Reflected XSS via search clean-URL route CVSS 4.0MEDIUM 5.3
  • TI-2023-30215 Serendipity 2.4.0 Stored Cross-Site Scripting via Admin Entry Creation CVSS 4.0MEDIUM 5.1
See all 64 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences