---
id: "CVE-2026-126546"
page: "https://infrastack.ai/live/CVE-2026-126546"
kind: "vulnerability"
aliases: ["CVE-2026-126546"]
title: "Viber for iOS: crafted GIF with zero dimensions crashes the app"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["ios", "other", "viber"]
not_affected_if: ["android", "newer-version"]
published_at: "2026-11-11T01:17:16+00:00"
first_seen_at: "2026-11-11T01:24:34+00:00"
updated_at: "2026-11-11T01:25:53+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126546", "first_seen_at": "2026-11-11T01:24:34+00:00"}]
exploit_sources: []
---

# Viber for iOS: crafted GIF with zero dimensions crashes the app

Link for people: https://infrastack.ai/live/CVE-2026-126546 (this .md is for agents)

Viber for iOS through 29.4.0.24 does not validate the logical screen width and height in GIF headers. A crafted GIF with zero dimensions triggers an uncaught exception that aborts the app when the image is opened, so an attacker can crash it.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Open Viber, go to Settings > About and compare the version with `29.4.0.24`, which is the last affected version according to the description.

## Timeline

- 2026-11-11T01:24:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126546

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/viber-for-ios-through-29.4.0.24-denial-of-service-via-malformed-gif

## From the sources

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.

---

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