Buffer overflow in Tenda Ac20
CVE-2025-8939
A vulnerability was determined in Tenda AC20 up to 16.03.08.12. Affected is an unknown function of the file /goform/WifiGuestSet. The manipulation of the argument shareSpeed leads to buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.009 (58.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: +0.000
Affected products
- Tenda Ac20 — versions 16.03.08.0, 16.03.08.1, 16.03.08.2
- Tenda Ac20 Firmware
Weakness classification (CWE)
Public proof-of-concept exploits
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/lin-3-start/lin-cve/blob/main/Tenda AC20/Tenda AC20.md (related, Exploit, Third Party Advisory)
- github.com/lin-3-start/lin-cve/blob/main/Tenda AC20/Tenda AC20.md (Exploit, Third Party Advisory, exploit)
- www.tenda.com.cn/ (Product, product)
Frequently asked questions
- What is CVE-2025-8939?
- CVE-2025-8939 is a high-severity vulnerability in Tenda Ac20, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2025-08-14.
- How severe is CVE-2025-8939?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2025-8939 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.