How severe is CVE-2026-9303?

CVE-2026-9303 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-9303 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-9303?

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

Does CVE-2026-9303 have an EU (EUVD) identifier?

Yes. CVE-2026-9303 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31539.

When was CVE-2026-9303 published?

CVE-2026-9303 was published on 2026-05-23 and last updated on 2026-06-17.

CVE-2026-9303

CVE-2026-9303 is a medium-severity vulnerability with a CVSS 3.x base score of 4.3. 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-352.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 5.0
CVSS v4: 2.1
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31539
Weakness: CWE-352
Published: 2026-05-23
Last modified: 2026-06-17

Description

A vulnerability was identified in calcom cal.diy up to 4.9.4. Impacted is an unknown function. The manipulation leads to cross-site request forgery. It is possible to initiate the attack remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

Frequently asked questions

What is CVE-2026-9303?: A vulnerability was identified in calcom cal.diy up to 4.9.4. Impacted is an unknown function. The manipulation leads to cross-site request forgery. It is possible to initiate the attack remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.
How severe is CVE-2026-9303?: CVE-2026-9303 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-9303 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-9303?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-9303 have an EU (EUVD) identifier?: Yes. CVE-2026-9303 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31539.
When was CVE-2026-9303 published?: CVE-2026-9303 was published on 2026-05-23 and last updated on 2026-06-17.

References

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