# CVE-2026-21091: Samsung libcodec2secevrcdec out-of-bounds write

Source: https://junglewise.ai/threats/cve-2026-21091-samsung-libcodec2secevrcdec-out-of-bounds-write  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-09. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-21091 · Severity: high · CVSS 7.8 · Published 2026-09-09

A memory writing vulnerability exists in Samsung's codec library used in mobile devices. A local attacker can exploit this to write data beyond intended memory boundaries, potentially corrupting system memory, crashing the device, or executing malicious code with elevated privileges.

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

## Quick answers

**Is CVE-2026-21091 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-21091 being exploited in the wild.

**How severe is CVE-2026-21091?** High severity, with a CVSS score of 7.8, published 9 September 2026.

**Which products and versions are affected?** Samsung Android firmware Prior to SMR September 2026 Release 1.

**Is there a fix for CVE-2026-21091?** A patch was published on 2026-09: Samsung Mobile SMR September 2026 Release 1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-21091 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-21091?** 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.

## Technical details

The vulnerability is an out-of-bounds write flaw in libcodec2secevrcdec.so, a component of Samsung's codec processing library. The vulnerability requires local access to the affected system and can be triggered to write arbitrary data beyond allocated memory boundaries. Successful exploitation may lead to memory corruption, denial of service, or potential privilege escalation depending on the memory context and attack sophistication. The issue was patched in Samsung Mobile's SMR September 2026 Release 1 security update.

## Affected products

- Samsung Android firmware Prior to SMR September 2026 Release 1

## Timeline

- 2026-09-09: disclosed
- 2026-09: patched: Samsung Mobile SMR September 2026 Release 1

## References

- [https://security.samsungmobile.com/securityUpdate.smsb?year=2026&month=09](https://security.samsungmobile.com/securityUpdate.smsb?year=2026&month=09)

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