CVE-2026-88377

MEDIUM
Published Sep 24, 2026 Modified Sep 29, 2026 CWE-191

Description

Bento4 1.6.0.0 contains an integer underflow vulnerability in the avcC and hvcC configuration atom parsers. A specially crafted MP4 file containing an atom with a declared size smaller than AP4_ATOM_HEADER_SIZE can cause AP4_AvccAtom::Create() or AP4_HvccAtom::Create() to underflow the payload-size calculation. The resulting oversized buffer operation can cause invalid or NULL pointers to be passed to the AP4_DataBuffer copy path, resulting in application termination and denial of service.

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CVSS v3.1 Score

6.2
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0012
Probability of exploitation
0.02%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-191 CWE-191

References

Frequently Asked Questions

What is CVE-2026-88377? +
Bento4 1.6.0.0 contains an integer underflow vulnerability in the avcC and hvcC configuration atom parsers. A specially crafted MP4 file containing an atom with a declared size smaller than AP4_ATOM_HEADER_SIZE can cause AP4_AvccAtom::Create() or AP4_HvccAtom::Create() to underflow the payload-size calculation. The resulting oversized buffer operation can cause invalid or NULL pointers to be passed to the AP4_DataBuffer copy path, resulting in application termination and denial of service. It has a CVSS v3.1 base score of 6.2 (MEDIUM).
How severe is CVE-2026-88377? +
CVE-2026-88377 has a CVSS v3.1 score of 6.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0012, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-88377? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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