CVE-2026-52881

CRITICALCVSS · not yet scored

Also known asGHSA-vcrw-4xvv-jh49 (GitHub Security Advisories)

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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: —CVSS v2: —Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

MantisBT: Reflected XSS in admin/install.php via unescaped printf

MantisBT 2.28.3 and earlier contains six reflected XSS injection points in /admin/install.php. User-supplied parameters are echoed into HTML without escaping via an unescaped printf format string. No authentication is required.

A Content Security Policy (script-src 'self') prevents inline JavaScript execution, but the CSP is missing a form-action directive, allowing exploitation via credential-phishing form injection and open redirects.

Impact

  • Credential phishing: Attacker crafts a URL that renders a fake login form on the real MantisBT admin page. Admin credentials are submitted to an attacker-controlled server.
  • Open redirect: Victim is silently redirected to a phishing or malware site.
  • UI manipulation: CSS injection can hide legitimate page content and overlay attacker-controlled HTML, enabling social engineering.

Patches

  • https://github.com/mantisbt/mantisbt/commit/297773fbb238c39a153bd888431b41a176132098

Workarounds

Remove the /admin directory, as recommended in the Admin Guide

Resources

Credits

McCaulay Hudson (@_McCaulay) of watchTowr

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
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EPSS %ILE
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KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

EG Severity
Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
EG Likelihood
Unknown (no EPSS on record)Unknown, not low: FIRST has published no EPSS probability for this CVE.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the BOD 26-04 block below.

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 15, 2026

Last Modified

July 15, 2026

Vendor Advisories for CVE-2026-52881(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 rangeFix by version rangeDependents
mantisbt/mantisbt2.10.0 ... 2.9.1 (78 versions)
  • every version up to 2.28.4: fixed in 2.28.4
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Data Freshness Timeline

(refreshed 1× in last 7d / 7× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-25 14:21 UTCEG score recompute
  2. 2026-10-18 03:32 UTCEG score recompute
  3. 2026-10-12 15:58 UTCEG score recompute
  4. 2026-10-11 19:41 UTCEG score recompute
  5. 2026-10-11 16:56 UTCEG score recompute
  6. 2026-10-11 14:19 UTCEG score recompute
  7. 2026-10-01 12:38 UTCEG score recompute
  8. 2026-08-01 17:14 UTCEG score recompute
  9. 2026-07-26 11:32 UTCEG score recompute
  10. 2026-07-23 03:19 UTCEG score recompute
  11. 2026-07-15 18:54 UTCEG score recompute

Frequently asked(3)

What is CVE-2026-52881?
CVE-2026-52881 is a critical-severity vulnerability; its CVE record was published on July 15, 2026. MantisBT: Reflected XSS in admin/install.php via unescaped printf MantisBT 2.28.3 and earlier contains six reflected XSS injection points in /admin/install.php. User-supplied parameters are echoed into HTML without escaping via an unescaped printf format string. No authentication is required. A…
When was the CVE record for CVE-2026-52881 published?
The CVE record for CVE-2026-52881 was published on July 15, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 15, 2026; the record at its source may have been updated since.
How do I remediate CVE-2026-52881?
A fix for CVE-2026-52881 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-52881 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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