Buffer overflow in Totolink A720r
CVE-2026-82539
A vulnerability was determined in TOTOLINK A720R 4.1.5cu.630_B20250509. This impacts the function setMacFilterRules of the file cstecgi.cgi of the component MAC Filtering. Executing a manipulation of the argument desc can lead to memory corruption. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.008 (56.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.008 · change: +0.002
Affected products
- Totolink A720r — versions 4.1.5cu.630_B20250509
Weakness classification (CWE)
Public proof-of-concept exploits
References
- vuldb.com/vuln/397055 (technical-description, vdb-entry)
- vuldb.com/vuln/397055/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-82539 (third-party-advisory)
- vuldb.com/submit/888696 (third-party-advisory)
- github.com/Xernary/CVE-2026-82539 (exploit)
- www.totolink.net/ (product)
Frequently asked questions
- What is CVE-2026-82539?
- CVE-2026-82539 is a critical-severity vulnerability in Totolink A720r, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.1/10. Published 2026-08-30.
- How severe is CVE-2026-82539?
- Critical severity. CVSS v3 base score is 9.1 out of 10.
- Is CVE-2026-82539 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.