Summary
OpenClaw: ACP prompt-size checks missing in local stdio bridge could reduce responsiveness with very large inputs
Vulnerability
The ACP bridge accepted very large prompt text blocks and could assemble oversized prompt payloads before forwarding them to chat.send.
Because ACP runs over local stdio, this mainly affects local ACP clients (for example IDE integrations) that send unusually large inputs.
Affected Packages / Versions
- Package:
openclaw(npm) - Affected versions:
<= 2026.2.17 - Patched version:
2026.2.18(planned next release)
Affected Components
src/acp/event-mapper.tssrc/acp/translator.ts
Fix Commit(s)
732e53151e8fbdfc0501182ddb0e900878bdc1e3ebcf19746f5c500a41817e03abecadea8655654a63e39d7f57ac4ad4a5e38d17e7394ae7c4dd0b9c
Thanks @aether-ai-agent for reporting.
Impact
- Local ACP sessions may become less responsive when very large prompts are submitted
- Larger-than-expected model usage/cost when oversized text is forwarded
- No privilege escalation and no direct remote attack path in the default ACP model
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
- Enforce a 2 MiB prompt-text limit before concatenation
- Count inter-block newline separator bytes during pre-concatenation size checks
- Keep final outbound message-size validation before
chat.send - Avoid stale active-run session state when oversized prompts are rejected
- Add regression tests for oversize rejection and active-run cleanup
Frequently Asked Questions
- What is CVE-2026-27576? CVE-2026-27576 is a medium-severity uncontrolled resource consumption vulnerability in openclaw (npm), affecting versions <= 2026.2.17. It is fixed in 2026.2.19. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- Which versions of openclaw are affected by CVE-2026-27576? openclaw (npm) versions <= 2026.2.17 is affected.
- Is there a fix for CVE-2026-27576? Yes. CVE-2026-27576 is fixed in 2026.2.19. Upgrade to this version or later.
- Is CVE-2026-27576 exploitable, and should I be worried? Whether CVE-2026-27576 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-27576 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-27576? Upgrade
openclawto 2026.2.19 or later.