BacklinkSpeed 2.4 - Buffer Overflow PoC (SEH)

published 2026-01-29 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2020-30909

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits: 0; none known

BacklinkSpeed 2.4 contains a buffer overflow vulnerability that allows attackers to corrupt the Structured Exception Handler (SEH) chain through malicious file import. Attackers can craft a specially designed payload file to overwrite SEH addresses, potentially executing arbitrary code and gaining control of the application.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 9 mo ago (2026-01-29)

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

exploit-db.com https://www.exploit-db.com/exploits/48726 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.4	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	4.0	8.4	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

Dummysoftware BacklinkSpeed

Classification

Weakness

CWE-121 Stack-based Buffer Overflow

References

exploit-db.com /exploits/48726
exploit
dummysoftware.com
product
dummysoftware.com /backlinkspeed.html
product
vulncheck.com /advisories/backlinkspeed-buffer-overflow-poc-seh
third-party-advisory

Sources

CVE List CVE-2020-36997
NVD CVE-2020-36997

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary