How severe is CVE-2026-55790?

CVE-2026-55790 has a CVSS 4.0 base score of 7.4, rated high severity.

Is CVE-2026-55790 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-55790?

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.

When was CVE-2026-55790 published?

CVE-2026-55790 was published on 2026-07-01 and last updated on 2026-07-02.

CVE-2026-55790

CVE-2026-55790 is a high-severity vulnerability with a CVSS 4.0 base score of 7.4. 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 7.4)
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Published: 2026-07-01
Last modified: 2026-07-02

Description

Craft CMS is a content management system (CMS). In versions 5.0.0-RC1 through 5.9.22 and 4.0.0-RC1 through 4.17.15, an attacker with only a GitHub account can plant a JavaScript payload in a craftcms/cms issue title. When a Craft admin uses the CraftSupport widget’s "Give feedback" screen and types a search term that returns the poisoned issue, the payload executes in the admin’s control panel session. No control panel account or elevated privileges are required on the attacker’s side. This issue has been fixed in versions 4.17.16 and 5.9.23.

Frequently asked questions

What is CVE-2026-55790?: Craft CMS is a content management system (CMS). In versions 5.0.0-RC1 through 5.9.22 and 4.0.0-RC1 through 4.17.15, an attacker with only a GitHub account can plant a JavaScript payload in a craftcms/cms issue title. When a Craft admin uses the CraftSupport widget’s "Give feedback" screen and types a search term that returns the poisoned issue, the payload executes in the admin’s control panel session. No control panel account or elevated privileges are required on the attacker’s side. This issue has been fixed in versions 4.17.16 and 5.9.23.
How severe is CVE-2026-55790?: CVE-2026-55790 has a CVSS 4.0 base score of 7.4, rated high severity.
Is CVE-2026-55790 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-55790?: 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.
When was CVE-2026-55790 published?: CVE-2026-55790 was published on 2026-07-01 and last updated on 2026-07-02.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

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CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

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