CVE-2026-126546 Viber for iOS through 29.4.0.24 Denial of Service via Malformed GIF
Attackers can crash Viber for iOS by sending a GIF with zero dimensions that the app opens.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Harmful if only installed
- No
- Needs a specific call
- No
- Fix
- None listed
What is CVE-2026-126546?
CVE-2026-126546 is a medium-severity denial of service vulnerability in Rakuten Viber Viber for iOS, published on 11 Nov 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Viber for iOS through 29.4.0.24 fails to validate the logical screen width and height in received GIF headers, allowing attackers to crash the app. Attackers can send a crafted GIF with zero dimensions that triggers an uncaught NSInternalInconsistencyException, aborting the app with SIGABRT when opened.
Weakness: CWE-248
Which versions are affected by CVE-2026-126546?
An affected version is exposed as installed. No special setting or call is needed.
How do I fix CVE-2026-126546?
No fix has been published for CVE-2026-126546 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-2026-126546 being exploited?
There is no known exploitation of CVE-2026-126546 in the wild and no public exploit code.
Sources
Also known as GHSA-rx59-vg9j-fpm4.