How severe is CVE-2026-40607?

CVE-2026-40607 has a CVSS 4.0 base score of 7.5, rated high severity.

Is CVE-2026-40607 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40607?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40607 have an EU (EUVD) identifier?

Yes. CVE-2026-40607 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31495.

When was CVE-2026-40607 published?

CVE-2026-40607 was published on 2026-05-22 and last updated on 2026-06-17.

CVE-2026-40607

CVE-2026-40607 is a high-severity vulnerability with a CVSS 4.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 4.0 base score 7.5)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31495
Weakness: CWE-79
Published: 2026-05-22
Last modified: 2026-06-17

Description

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).

Frequently asked questions

What is CVE-2026-40607?: 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).
How severe is CVE-2026-40607?: CVE-2026-40607 has a CVSS 4.0 base score of 7.5, rated high severity.
Is CVE-2026-40607 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40607?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40607 have an EU (EUVD) identifier?: Yes. CVE-2026-40607 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31495.
When was CVE-2026-40607 published?: CVE-2026-40607 was published on 2026-05-22 and last updated on 2026-06-17.

References

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