# CVE-2026-21124: Samsung HEIF decoder improper input validation in cover image handling

Source: https://junglewise.ai/threats/cve-2026-21124-improper-input-validation-in-getting-cover-image-in-libsimba  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-12. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-21124 · Severity: info · Published 2026-10-12

Samsung's HEIF image decoder library contains an improper input validation vulnerability in its cover image handling routine. A local attacker could exploit this flaw to execute arbitrary code on a device, potentially gaining full system control.

Technologies: [Samsung Android firmware](https://junglewise.ai/threats/technologies/android-firmware). Vendors: [Samsung](https://junglewise.ai/threats/vendors/samsung).

## Quick answers

**Is CVE-2026-21124 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-21124 being exploited in the wild.

**How severe is CVE-2026-21124?** Informational severity, published 12 October 2026.

**Which products and versions are affected?** Samsung Android firmware prior to SMR Oct-2026 Release 1.

**Is there a fix for CVE-2026-21124?** Yes: fixed in SMR Oct-2026 Release 1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-21124 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-21124?** Check whether you run Samsung Android firmware at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in SMR Oct-2026 Release 1

## Technical details

An improper input validation weakness exists in the libsimba.heifdec.media.samsung.so library's cover image processing function. The vulnerability allows local attackers to trigger arbitrary code execution through a malformed HEIF image file. No public exploit is known at this time.

## Affected products

- Samsung Android firmware prior to SMR Oct-2026 Release 1

## Timeline

- 2026-10-12: disclosed

## References

- [https://security.samsungmobile.com/securityUpdate.smsb?year=2026&month=10](https://security.samsungmobile.com/securityUpdate.smsb?year=2026&month=10)

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