GPAC MP4Box isom_intern.c MergeFragment null pointer dereference

published 2026-05-26 5 mo ago modified 2026-07-23 3 mo ago also EUVD-2026-31945

cvss: 3.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits: 0; none known

A security flaw has been discovered in GPAC up to 2.4.0. Affected is the function MergeFragment of the file src/isomedia/isom_intern.c of the component MP4Box. The manipulation results in null pointer dereference. The attack needs to be approached locally. The exploit has been released to the public and may be used for attacks. The patch is identified as 525bf1af642c30af04e4df5345e6d798c0a4d8a1. It is advisable to implement a patch to correct this issue.

Patch / fix

links 1

github.com/makesoftwaresafe/gpac@525bf1a commit

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-26)

Exploit prediction

0.11% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/user-attachments/files/27196918/poc.zip referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	4.8	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	3.3	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA	3.0	3.3	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA	2.0	1.7	AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:OF/RC:C
CNA	4.0	1.9	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA	3.1	3.3	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CNA	2.0	1.7	AV:L/AC:L/Au:S/C:N/I:N/A:P

Affected products

n/a GPAC

Classification

Weakness

CWE-476 NULL Pointer Dereference
CWE-404 Improper Resource Shutdown or Release

References

github.com /makesoftwaresafe/gpac/commit/525bf1af642c30af04e4df5345e6d798c0a4d8a1
patch
github.com /user-attachments/files/27196918/poc.zip
exploit
vuldb.com /vuln/365629
vdb-entry, technical-description
vuldb.com /vuln/365629/cti
signature, permissions-required
vuldb.com /submit/816075
third-party-advisory
github.com /gpac/gpac/issues/3549
issue-tracking
github.com /gpac/gpac/
product

Sources

CVE List CVE-2026-9567
NVD CVE-2026-9567

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary