What is CVE-2025-55661?

CVE-2025-55661 is a medium-severity vulnerability in Gpac, classified under Heap-based Buffer Overflow. CVSS score: 5.5/10. Published 2026-06-15.

How severe is CVE-2025-55661?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Gpac

CVE-2025-55661

A heap buffer overflow in the Opus audio stream parser component of GPAC MP4Box v2.4 allows attackers to cause a Denial of Service (DoS) via supplying a crafted MP4 file.

Vulnerability class: Buffer Overflow

Published 2026-06-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (15.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Gpac

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

infosec.exchange/@sigdevel/116733907390103029 (Exploit, Patch, Third Party Advisory, Mitigation)
af854a3a-2127-422b-91ae-364da2661108 (Exploit, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2025-55661?: CVE-2025-55661 is a medium-severity vulnerability in Gpac, classified under Heap-based Buffer Overflow. CVSS score: 5.5/10. Published 2026-06-15.
How severe is CVE-2025-55661?: Medium severity. CVSS v3 base score is 5.5 out of 10.