Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-40607

HIGH · 7.5 CVSS v4.0 Published 2026-05-22
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
81/100
Remediation priority · High
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.11.0 through 2.28.1, a Stored XSS vulnerability is caused by incorrect escaping of a saved filter's owner, allowing an attacker to inject arbitrary HTML on systems where $g_show_user_realname = ON. Note that By default, only users with Manager access level or above can save their filters publicly. This issue has been fixed in version 2.28.2. If developers are unable to update immediately, they can work around this issue by preventing display of users' real names (set $g_ show_user_realname = OFF; in configuration), and restricting the ability to store filters (set $g_stored_query_create_threshold / $g_stored_query_create_shared_threshold to NOBODY).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-79

Untrusted input is placed into a web page without being neutralised, so an attacker's markup or script executes in another user's browser. That can hijack sessions, capture keystrokes, or silently perform actions as the victim. Fixing it properly means context-aware output encoding everywhere data meets HTML, backed by a content-security policy as a second line of defence.

General guidance for the cross-site scripting (xss) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch github.com →
Recommended fix High confidence

2.28.2

  1. 1. Back up your MantisBT installation and database before upgrading.
  2. 2. Download MantisBT version 2.28.2 from the official MantisBT repository or release page.
  3. 3. Extract the new version files to your web server, replacing the existing installation.
  4. 4. Run the administration scripts to upgrade the database schema if required (e.g., /admin/install.php).
  5. 5. Verify the installation by logging in and testing filter functionality.
  6. 6. Alternatively, if you cannot upgrade immediately, edit your config file (config/config.php) to add: $g_show_user_realname = OFF;
  7. 7. Additionally, restrict filter creation by setting in config: $g_stored_query_create_threshold = NOBODY; and $g_stored_query_create_shared_threshold = NOBODY;

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-40607 in production — separate from our analysis above.

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What this is

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