CVE-2026-13523 GPAC ISOBMFF base_encoding.c data amplification
A local attacker can cause denial of service in GPAC via data amplification in the ISOBMFF parser, requiring a patch to mitigate.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-13523?
CVE-2026-13523 is a medium-severity denial of service vulnerability in GPAC, published on 29 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A weakness has been identified in GPAC up to 26.02.0. This affects an unknown part of the file src/utils/base_encoding.c of the component ISOBMFF Parser. Executing a manipulation can lead to highly compressed data. The attack needs to be launched locally. The exploit has been made available to the public and could be used for attacks. This patch is called 297f2d8d1f493d8b241330533cd47f7da758aeb3. A patch should be applied to remediate this issue. The vendor confirms: "We added a check on inflate output size, if it surpasses 32 times the input size we stop in error. This value could be adjusted later."
Which versions are affected by CVE-2026-13523?
How do I fix CVE-2026-13523?
No fix has been published for CVE-2026-13523 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-13523 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-13523 exists.
Sources
Also known as DEBIAN-CVE-2026-13523, GHSA-c4wq-769x-vwcv, UBUNTU-CVE-2026-13523.