CVE-2026-20797

Appliance termination via API stack overwrite

Published Feb 27, 2026 · Updated Feb 27, 2026

Stack-based buffer overflow in Copeland XWEB PRO 1.12.1 and earlier allows remote attackers to terminate the appliance via an API request. An undisclosed API route writes attacker-controlled data past a stack buffer, corrupting the process stack; Copeland has not identified the route or input field. No authentication or user interaction is required, but the attacker must share an adjacent network, and the reported consequence is program termination.

CVSS severity4.3
Medium
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stack-based buffer overflow in Copeland XWEB PRO 1.12.1 and earlier allows remote attackers to terminate the appliance via an API request. An undisclosed API route writes attacker-controlled data past a stack buffer, corrupting the process stack; Copeland has not identified the route or input field. No authentication or user interaction is required, but the attacker must share an adjacent network, and the reported consequence is program termination.

The record

CVE
CVE-2026-20797
Published
Feb 27, 2026
Updated
Feb 27, 2026
Vendor
Copeland LP
Product
XWEB 300D PRO
Classifications
CWE-121, CWE-787, T1499, T0814
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.12.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Copeland LP · XWEB 300D PROversion=0 <=1.12.1
Copeland LP · XWEB 500D PROversion=0 <=1.12.1
Copeland LP · XWEB 500B PROversion=0 <=1.12.1

Published CVSS scores

4.3ICS-CERTCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo