CVE-2026-28394

OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.

OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.

Summary

The web_fetch tool could be used to crash the OpenClaw Gateway process (OOM / resource exhaustion) by fetching and attempting to parse attacker-controlled web pages with oversized response bodies or pathological HTML nesting.

Affected Packages / Versions

• Package: openclaw (npm)
• Affected versions: <= 2026.2.14
• Fixed versions: >= 2026.2.15

Impact

An attacker can social-engineer a user (or any automation that uses web_fetch) into fetching a malicious URL that returns extremely large or deeply nested HTML. The Gateway may exhaust memory or become unresponsive, causing a denial of service.

Fix

The Gateway now caps the downloaded response body size before any HTML parsing and adds additional guards to avoid running Readability/DOM parsing on pathological HTML.

Fix Commit(s)

• 166cf6a3e04c7df42bea70a7ad5ce2b9df46d147

Release Process Note

This advisory is prepared for the next npm release. Once openclaw@2026.2.15 is published, publish this advisory without further edits.

Thanks @xuemian168 for reporting.

OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.

OpenClaw versions prior to 2026.2.15 contain a denial of service vulnerability in the web_fetch tool that allows attackers to crash the Gateway process through memory exhaustion by parsing oversized or deeply nested HTML responses. Remote attackers can social-engineer users into fetching malicious URLs with pathological HTML structures to exhaust server memory and cause service unavailability.

Summary

The web_fetch tool could be used to crash the OpenClaw Gateway process (OOM / resource exhaustion) by fetching and attempting to parse attacker-controlled web pages with oversized response bodies or pathological HTML nesting.

Affected Packages / Versions

• Package: openclaw (npm)
• Affected versions: <= 2026.2.14
• Fixed versions: >= 2026.2.15

Impact

An attacker can social-engineer a user (or any automation that uses web_fetch) into fetching a malicious URL that returns extremely large or deeply nested HTML. The Gateway may exhaust memory or become unresponsive, causing a denial of service.

Fix

The Gateway now caps the downloaded response body size before any HTML parsing and adds additional guards to avoid running Readability/DOM parsing on pathological HTML.

Fix Commit(s)

• 166cf6a3e04c7df42bea70a7ad5ce2b9df46d147

Release Process Note

This advisory is prepared for the next npm release. Once openclaw@2026.2.15 is published, publish this advisory without further edits.

Thanks @xuemian168 for reporting.