How severe is CVE-2026-30040?

CVE-2026-30040 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2026-30040 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-30040?

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

When was CVE-2026-30040 published?

CVE-2026-30040 was published on 2026-06-26.

CVE-2026-30040

CVE-2026-30040 is a medium-severity vulnerability with a CVSS 3.x base score of 6.5. 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-122.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-122
Published: 2026-06-26
Last modified: 2026-06-26

Description

A heap overflow in the FSViewer.exe process of FastStone Image Viewer v8.3 allows attackers to cause a execute arbitrary code in the context of the current process via supplying a crafted JPEG 2000 (JP2) file.

Frequently asked questions

What is CVE-2026-30040?: A heap overflow in the FSViewer.exe process of FastStone Image Viewer v8.3 allows attackers to cause a execute arbitrary code in the context of the current process via supplying a crafted JPEG 2000 (JP2) file.
How severe is CVE-2026-30040?: CVE-2026-30040 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2026-30040 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-30040?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-30040 published?: CVE-2026-30040 was published on 2026-06-26.

References

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