How severe is CVE-2026-9053?

CVE-2026-9053 has a CVSS 4.0 base score of 6.9, rated medium severity.

Is CVE-2026-9053 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-9053?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-9053 have an EU (EUVD) identifier?

Yes. CVE-2026-9053 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31401.

When was CVE-2026-9053 published?

CVE-2026-9053 was published on 2026-05-22 and last updated on 2026-06-17.

CVE-2026-9053

CVE-2026-9053 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.9. 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-434.

Key facts

Severity: Medium (CVSS 4.0 base score 6.9)
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31401
Weakness: CWE-434
Published: 2026-05-22
Last modified: 2026-06-17

Description

Mothra would respect a default value given by a website for HTML file upload forms. An attacker could craft a website with a malicious default file path, and then conceal this form element.

Frequently asked questions

What is CVE-2026-9053?: Mothra would respect a default value given by a website for HTML file upload forms. An attacker could craft a website with a malicious default file path, and then conceal this form element.
How severe is CVE-2026-9053?: CVE-2026-9053 has a CVSS 4.0 base score of 6.9, rated medium severity.
Is CVE-2026-9053 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-9053?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-9053 have an EU (EUVD) identifier?: Yes. CVE-2026-9053 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31401.
When was CVE-2026-9053 published?: CVE-2026-9053 was published on 2026-05-22 and last updated on 2026-06-17.

References

https://git.9front.org/plan9front/9front/d145acc9ef0da47131af6ad94e87264e04870d47/commit.html

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