Buffer overflow in Yealink Sip-T46u
CVE-2026-12220
A vulnerability has been found in Yealink SIP-T46U 108.86.0.118. This affects the function mod_upgrade.SparePartsUpload of the file /api/upgrade/accupgradebychunk of the component Firmware Chunk Upload handler. Such manipulation of the argument uid leads to stack-based buffer overflow. The attack can only be initiated within the local network. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure and is working on a patch to fix it.
Vulnerability class: Buffer Overflow
EPSS: 0.004 (30.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Yealink Sip-t46u — versions 108.86.0.118
Weakness classification (CWE)
References
- cna@vuldb.com (exploit, patch, broken-link)
- cna@vuldb.com (third-party-advisory)
- cna@vuldb.com (third-party-advisory)
- cna@vuldb.com (technical-description, vdb-entry)
- cna@vuldb.com (signature, permissions-required)
Frequently asked questions
- What is CVE-2026-12220?
- CVE-2026-12220 is a high-severity vulnerability in Yealink Sip-T46u, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.0/10. Published 2026-06-15.
- How severe is CVE-2026-12220?
- High severity. CVSS v3 base score is 8.0 out of 10.