Vulnerability-Lookup

CVE-2026-47156 (GCVE-0-2026-47156)

Vulnerability from cvelistv5 – Published: 2026-09-09 16:06 – Updated: 2026-09-10 14:56

Title

MantisBT: SOAP API Authentication Bypass with Privilege Escalation to Administrator

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.

Severity

9.3 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-09 19:42 UTC

CWE

CWE-287 - Improper Authentication
CWE-639 - Authorization Bypass Through User-Controlled Key

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/mantisbt/mantisbt/security/adv…	x_refsource_CONFIRM
https://github.com/mantisbt/mantisbt/commit/e3571…	x_refsource_MISC
https://mantisbt.org/bugs/view.php?id=37121	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
mantisbt	mantisbt	Affected: < 2.28.4	guessed

Show details on NVD website

JSON

To clipboard

{
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                "id": "CVE-2026-47156",
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FKIE_CVE-2026-47156

Vulnerability from fkie_nvd - Published: 2026-09-09 17:17 - Updated: 2026-09-10 15:53

Severity

9.3 (Critical) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/mantisbt/mantisbt/commit/e3571c319b1721b41b0dc4b5b5203cbdcbe0c2ee
	security-advisories@github.com	https://github.com/mantisbt/mantisbt/security/advisories/GHSA-c2xg-qjqw-2v98
	security-advisories@github.com	https://mantisbt.org/bugs/view.php?id=37121

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "mantisbt",
          "vendor": "mantisbt",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.28.4"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MantisBT is an open source bug tracker. Versions 2.28.3 and earlier contain a critical authentication bypass in the SOAP API\u0027s 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\u0027s 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\u0027s MANTIS_STRING_COOKIE cookie after login) to impersonate the administrator via the SOAP API. The REST API is NOT affected. The REST API\u0027s 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."
    }
  ],
  "id": "CVE-2026-47156",
  "lastModified": "2026-09-10T15:53:23.707",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
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          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
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  "references": [
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      "url": "https://github.com/mantisbt/mantisbt/commit/e3571c319b1721b41b0dc4b5b5203cbdcbe0c2ee"
    },
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    }
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  "vulnStatus": "Deferred",
  "weaknesses": [
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        },
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        }
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}

GHSA-C2XG-QJQW-2V98

Vulnerability from github – Published: 2026-07-15 16:45 – Updated: 2026-07-15 16:45

Summary

MantisBT: SOAP API Authentication Bypass with Privilege Escalation to Administrator

Details

MantisBT 2.28.3 and earlier contains 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.

Impact

Full administrator access to the SOAP API from zero prior access (with self-registration enabled, which is the default)
Read/write all issues including private issues and notes across all projects
Full data exfiltration of all bug reports, attachments, user accounts (id, name, email), and non-private configuration values via the 71 SOAP operations available
Destructive operations: delete projects, issues, attachments, tags, categories, and versions
Data manipulation: create/modify issues, impersonate reporters, manage project structure
Chains with other vulnerabilities: the SOAP admin access enables exploitation of SOAP vulnerabilities that require administrator privileges

Patches

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

Workarounds

None

Resources

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

Credits

MantisBT would like to thank McCaulay Hudson (@_McCaulay) of watchTowr for originally identifying and responsibly reporting the issue.

The vulnerability was subsequently discovered by other researchers, while the team was working on fixing and preparing the release. MantisBT credits them here, in chronological order of their reports: - Keitaro Yamazaki (@tyage) - Harrison Keating (@voraci0us) - Chandler Johnson (@chndlrx) - Bharat Devasani (@bharatdevasani)

Severity

9.3 (Critical)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.28.3"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "mantisbt/mantisbt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.28.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47156"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287",
      "CWE-639"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-15T16:45:22Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "MantisBT 2.28.3 and earlier contains a critical authentication bypass in the SOAP API\u0027s 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\u0027s password.\n\nThe 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\u0027s MANTIS_STRING_COOKIE cookie after login) to impersonate the administrator via the SOAP API.\n\nThe REST API is NOT affected. The REST API\u0027s AuthMiddleware derives the username server-side from the API token or session cookie, so the username cannot be spoofed.\n\nThe 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.\n\n### Impact\n- Full administrator access to the SOAP API from zero prior access (with self-registration enabled, which is the default)\n- Read/write all issues including private issues and notes across all projects\n- Full data exfiltration of all bug reports, attachments, user accounts (id, name, email), and non-private configuration values via the 71 SOAP operations available\n- Destructive operations: delete projects, issues, attachments, tags, categories, and versions\n- Data manipulation: create/modify issues, impersonate reporters, manage project structure\n- Chains with other vulnerabilities: the SOAP admin access enables exploitation of SOAP vulnerabilities that require administrator privileges\n\n### Patches\n- https://github.com/mantisbt/mantisbt/commit/e3571c319b1721b41b0dc4b5b5203cbdcbe0c2ee\n\n### Workarounds\nNone\n\n### Resources\n- https://mantisbt.org/bugs/view.php?id=37121\n\n### Credits\nMantisBT would like to thank McCaulay Hudson ([@_McCaulay](https://x.com/_mccaulay)) of [watchTowr](https://labs.watchtowr.com/) for originally identifying and responsibly reporting the issue.\n\nThe vulnerability  was subsequently discovered by other researchers, while the team was working on fixing and preparing the release. MantisBT credits them here, in chronological order of their reports: \n- Keitaro Yamazaki (@tyage) \n- Harrison Keating (@voraci0us)\n- Chandler Johnson (@chndlrx)\n- Bharat Devasani (@bharatdevasani)",
  "id": "GHSA-c2xg-qjqw-2v98",
  "modified": "2026-07-15T16:45:22Z",
  "published": "2026-07-15T16:45:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mantisbt/mantisbt/security/advisories/GHSA-c2xg-qjqw-2v98"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mantisbt/mantisbt/commit/e3571c319b1721b41b0dc4b5b5203cbdcbe0c2ee"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mantisbt/mantisbt"
    },
    {
      "type": "WEB",
      "url": "https://mantisbt.org/bugs/view.php?id=37121"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "MantisBT: SOAP API Authentication Bypass with Privilege Escalation to Administrator"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-47156 (GCVE-0-2026-47156)

FKIE_CVE-2026-47156

GHSA-C2XG-QJQW-2V98

Impact

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Workarounds

Resources

Credits

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