How severe is CVE-2026-40930?

CVE-2026-40930 has a CVSS 3.x base score of 5.4, 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 low.

Is CVE-2026-40930 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40930?

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

Does CVE-2026-40930 have an EU (EUVD) identifier?

Yes. CVE-2026-40930 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34287.

When was CVE-2026-40930 published?

CVE-2026-40930 was published on 2026-06-04 and last updated on 2026-06-17.

CVE-2026-40930

CVE-2026-40930 is a medium-severity vulnerability with a CVSS 3.x base score of 5.4. 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-436.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (10th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34287
Weakness: CWE-436
Published: 2026-06-04
Last modified: 2026-06-17

Description

LIBPNG is a reference library for use in applications that process PNG (Portable Network Graphics) raster image files. In version 1.8.0, three inter-frame chunk discard paths in the push-mode APNG parser clear the chunk-header flag without consuming the chunk body and CRC, allowing attacker-controlled bytes inside an ignored ancillary chunk to be reinterpreted as a fresh chunk header on the next call to `png_process_data`. Commit faf06924688b62d7c1654b5ceddedbde66ffadb4 fixes the issue.

Frequently asked questions

What is CVE-2026-40930?: LIBPNG is a reference library for use in applications that process PNG (Portable Network Graphics) raster image files. In version 1.8.0, three inter-frame chunk discard paths in the push-mode APNG parser clear the chunk-header flag without consuming the chunk body and CRC, allowing attacker-controlled bytes inside an ignored ancillary chunk to be reinterpreted as a fresh chunk header on the next call to `png_process_data`. Commit faf06924688b62d7c1654b5ceddedbde66ffadb4 fixes the issue.
How severe is CVE-2026-40930?: CVE-2026-40930 has a CVSS 3.x base score of 5.4, 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 low.
Is CVE-2026-40930 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40930?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40930 have an EU (EUVD) identifier?: Yes. CVE-2026-40930 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34287.
When was CVE-2026-40930 published?: CVE-2026-40930 was published on 2026-06-04 and last updated on 2026-06-17.

References

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