Quick answers
- Is CVE-2026-21066 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-21066 being exploited in the wild.
- How severe is CVE-2026-21066?
- High severity, with a CVSS score of 7.8, published 10 August 2026.
- Which products and versions are affected?
- Samsung Mobile Firmware prior to SMR Aug-2026 Release 1.
- Is there a fix for CVE-2026-21066?
- A patch was published on 2026-08: SMR Aug-2026 Release 1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-21066 attacked?
- It is attacked with local access, in device firmware.
- Am I affected by CVE-2026-21066?
- Check whether you run Samsung Mobile 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 stems from improper input validation in libcodec2_sec_flacdec.so, a FLAC audio decoder library used in Samsung firmware. An attacker with local access can craft malicious FLAC audio input that bypasses bounds checking, leading to an out-of-bounds write condition. This allows arbitrary memory corruption within the decoder process, potentially enabling privilege escalation, denial of service, or arbitrary code execution depending on process privileges and memory layout. The fix is available in Samsung Mobile's August 2026 Release 1 security update.
Affected products
- Samsung Mobile Firmware prior to SMR Aug-2026 Release 1
Timeline
- 2026-08-10: disclosed
- 2026-08: patched: SMR Aug-2026 Release 1