TI-2026-34746 Aliases CVE-2026-47156 GHSA-c2xg-qjqw-2v98

MantisBT: SOAP API Authentication Bypass with Privilege Escalation to Administrator

MEDIUM 49CWE-287Published 2026-09-09 · Updated 2026-09-10

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-287.

Summary

MantisBT is an open source bug tracker. Versions 2.28.3 and earlier contain a critical authentication bypass in the SOAP API's mci_check_login() function. Any user knowing any valid cookie_string can authenticate as any other user (knowing their username), including the administrator, without knowing the target's password. The vulnerability is exploitable with zero prior access on default MantisBT installations because self-registration is enabled by default ($g_allow_signup = ON). A self-registered user can use their own cookie_string (readable from their browser's MANTIS_STRING_COOKIE cookie after login) to impersonate the administrator via the SOAP API. The REST API is NOT affected. The REST API's AuthMiddleware derives the username server-side from the API token or session cookie, so the username cannot be spoofed. The Web UI is NOT affected. The Web UI authenticates via PHP session cookies (PHPSESSID) and validates the MANTIS_STRING_COOKIE against the logged-in user through auth_is_cookie_valid(). The username is derived server-side from the cookie, not supplied by the client. Version 2.28.4 contains a patch. No known workarounds are available.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00686 52nd percentileScored 2026-11-07

Fix Fixed mantisbt (mantisbt): 2.28.4mantisbt/mantisbt (Packagist): 2.28.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Total

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

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
mantisbt	mantisbt	before 2.28.4	2.28.4	Patch available	CNA
—	mantisbt/mantisbt (Packagist)	before 2.28.4	2.28.4	Patch available	GHSA-c2xg-qjqw-2v98

mantisbt Vendormantisbt Affected before 2.28.4 Fixed in 2.28.4 Patch available CNA
mantisbt/mantisbt (Packagist) Vendor— Affected before 2.28.4 Fixed in 2.28.4 Patch available GHSA-c2xg-qjqw-2v98

CPE names Threatist (inferred) · 1

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

CPE	Versions	Role	Vendor
cpe:2.3:a:mantisbt:mantisbt::::::::	—	—	mantisbt

cpe:2.3:a:mantisbt:mantisbt:*:*:*:*:*:*:*:* Versions — — ·mantisbt

Remediation

Fix · CNA mantisbt (mantisbt) Fixed in 2.28.4
Fix · GHSA-c2xg-qjqw-2v98 mantisbt/mantisbt (Packagist) Fixed in 2.28.4 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-47156
2026-10-03 Alias added: GHSA-c2xg-qjqw-2v98

References

Other 4

TI-2017-05251 MantisBT through 2.3.0 allows arbitrary password reset and unauthenticated admin access… CVSS 3.1HIGH 8.8
TI-2026-29334 MantisBT has Potential Referer-Based Reflected HTML Injection / XSS in Tag Update Page CVSS 4.0MEDIUM 6.9
TI-2014-05966 The XmlImportExport plugin in MantisBT 1.2.17 and earlier allows remote attackers to… CVSS 2.0HIGH 7.5
TI-2026-27192 MantisBT Bugnote Revision Page Leaks Private Issue Metadata After Issue Access Is Revoked CVSS 4.0MEDIUM 5.3
TI-2026-25495 MantisBT: Authorization Bypass in Global Profile Creation CVSS 4.0MEDIUM 5.3
TI-2026-26676 MantisBT: Privilege Escalation from Manager to Administrator CVSS 4.0MEDIUM 5.1

See all 144 →

Sources

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