Quick answers
- Is CVE-2026-12220 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-12220 being exploited in the wild.
- How severe is CVE-2026-12220?
- High severity, with a CVSS score of 8, published 15 June 2026.
- Which products and versions are affected?
- Yealink SIP-T46U 108.86.0.118.
- Is there a fix for CVE-2026-12220?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-12220 attacked?
- It is attacked from the adjacent network, in an operating system.
- Am I affected by CVE-2026-12220?
- Check whether you run Yealink SIP-T46U 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
A stack-based buffer overflow vulnerability exists in the Yealink SIP-T46U firmware version 108.86.0.118. The flaw is located within the mod_upgrade.SparePartsUpload function in the /api/upgrade/accupgradebychunk component. By manipulating the 'uid' argument during a firmware chunk upload request, an attacker with low-privileged access on the adjacent network can trigger the overflow. This can lead to arbitrary code execution or a complete system crash. As of the advisory date, the vendor has not responded to the disclosure, and no official patch is confirmed.
Affected products
- Yealink SIP-T46U 108.86.0.118
Timeline
- 2026-06-15: disclosed: Public disclosure of the vulnerability and exploit details.
- 2026-06-15: advisory