CVE-2026-47156

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 58% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.3
EG Score
9.3(medium)
EG Risk
57(Track)
EG Risk 57/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity93% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
42%
KEV
Not listed

Published

July 15, 2026

Last Modified

September 10, 2026

Advisory Details (3)

Auto-updated Sep 14, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
generic Patch Available🟡 PoC Available

0037121: CVE-2026-47156: SOAP API Authentication Bypass -> Privilege Escalation to Administrator - MantisBT

https://mantisbt.org/bugs/view.php?id=37121
github Patch Available

SOAP API Authentication Bypass with Privilege Escalation to Administrator · Advisory · mantisbt/mantisbt · GitHub

https://github.com/mantisbt/mantisbt/security/advisories/GHSA-c2xg-qjqw-2v98
github_commit

commit e3571c319b17 (mantisbt/mantisbt)

Fix landed in mantisbt/mantisbt commit e3571c319b17 — awaiting tagged release

https://github.com/mantisbt/mantisbt/commit/e3571c319b1721b41b0dc4b5b5203cbdcbe0c2ee

Vendor Advisories for CVE-2026-47156(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
mantisbt/mantisbt2.10.0 ... 2.9.1 (78 versions)2.28.4—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× in last 7d / 17× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 04:45 UTCEG score recompute
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 23:12 UTCEG score recompute
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-12 16:48 UTCEG score recompute
  9. 2026-09-12 15:01 UTCEPSS rescore
  10. 2026-09-11 21:45 UTCEG score recompute
  11. 2026-09-11 14:53 UTCEPSS rescore
  12. 2026-09-11 09:37 UTCEPSS rescore
  13. 2026-09-10 15:28 UTCEG score recompute
  14. 2026-09-10 15:01 UTCEG score recompute
  15. 2026-09-09 17:34 UTCEG score recompute
  16. 2026-09-09 16:30 UTCEG score recompute▲ 9.30
  17. 2026-09-09 16:25 UTCMITRE cvelistV5CVSS v3 → 9.3 · CVSS v4 → 9.3
  18. 2026-08-01 09:23 UTCEG score recompute
  19. 2026-07-26 11:35 UTCEG score recompute
  20. 2026-07-23 03:17 UTCEG score recompute
  21. 2026-07-15 16:54 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-47156?
CVE-2026-47156 is a critical vulnerability published on July 15, 2026. MantisBT is an open source bug tracker. Versions 2.28.3 and earlier contain a critical authentication bypass in the SOAP API's mcichecklogin() function. Any user knowing any valid cookiestring can authenticate as any other user (knowing their username), including the administrator, without knowing…
When was CVE-2026-47156 disclosed?
CVE-2026-47156 was first published in the National Vulnerability Database on July 15, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47156 actively exploited?
CVE-2026-47156 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 58.2% of all scored CVEs.
What is the CVSS score of CVE-2026-47156?
CVE-2026-47156 has a CVSS v3 base score of 9.3 (NVD).
How do I remediate CVE-2026-47156?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47156, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-47156

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