Buffer overflow in Copeland Xweb 300d Pro

CVE-2026-20797

A stack based buffer overflow exists in an API route of XWEB Pro version 1.12.1 and prior, enabling unauthenticated attackers to cause stack corruption and a termination of the program.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.008 (55.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-20797: held from 0.008 to 0.008.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20797?
CVE-2026-20797 is a medium-severity vulnerability in Copeland Xweb 300d Pro, classified under Out-of-bounds Write. CVSS score: 4.3/10. Published 2026-02-27.
How severe is CVE-2026-20797?
Medium severity. CVSS v3 base score is 4.3 out of 10.