What is the CVSS score of CVE-2026-20797?

CVE-2026-20797 has a CVSS 3.1 base score of 4.3 (Medium). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L. EPSS exploitation probability: 0.1%.

Which versions of Xweb 300d Pro Firmware are affected by CVE-2026-20797?

Organizations using an API route of XWEB Pro should be aware of moderate risk from CVE-2026-20797, a out-of-bounds write vulnerability rated CVSS 4.3.

Xweb 300d Pro Firmware CVE-2026-20797

MEDIUM

Out-of-bounds Write (CWE-787)

2026-02-27 ics-cert@hq.dhs.gov

Buffer Overflow Memory Corruption Xweb 300d Pro Firmware Xweb 500b Pro Firmware Xweb 500d Pro Firmware

4.3

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.3 MEDIUM

AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

CVE Published

Feb 27, 2026 - 02:16 nvd

MEDIUM 4.3

DescriptionCVE.org

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.

AnalysisAI

Unauthenticated attackers can exploit a stack buffer overflow in XWEB Pro firmware (versions 1.12.1 and earlier) through an unprotected API endpoint to corrupt memory and crash the affected device. This vulnerability impacts Xweb 500b Pro, 300d Pro, and 500d Pro models, causing denial of service with no authentication required. …

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Vulnerability AssessmentAI

Risk Assessment	CVSS 4.3 (MEDIUM). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An attacker without authentication could exploit this vulnerability to compromise the affected system.
Remediation	Monitor vendor advisories for a patch. … Detailed patch versions, workarounds, and compensating controls in full report.