CVE-2026-126546
Viber for iOS through 29.4.0.24 Denial of Service via Malformed GIF
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Viber for iOS Rakuten Viber |
≥ 0; ≤ 29.4.0.24 (affected, custom)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 5.3 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 4.3 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L | CNA: VulnCheck |
| 4.0 / 5.3 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/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 | NVD: [email protected] |
| 3.1 / 4.3 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://www.zeroscience.mk/en/vulnerabilities/ZSL-2026-6039.phpCNA: VulnCheck · third-party-advisory
- https://www.viber.com/CNA: VulnCheck · product
- https://www.vulncheck.com/advisories/viber-for-ios-through-29.4.0.24-denial-of-service-via-malformed-gifCNA: VulnCheck · third-party-advisory
- https://www.viber.com/[email protected]
- https://www.vulncheck.com/advisories/viber-for-ios-through-29.4.0.24-denial-of-service-via-malformed-gif[email protected]
- https://www.zeroscience.mk/en/vulnerabilities/ZSL-2026-6039.php[email protected]
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