How severe is CVE-2026-27576?

No CVSS score has been assigned to CVE-2026-27576 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-27576?

CVE-2026-27576 affects the following packages: openclaw (npm). Ecosystems affected: npm.

How do I fix CVE-2026-27576?

Update openclaw to 2026.2.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27576 is resolved across your whole dependency graph.

How do I detect CVE-2026-27576 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openclaw, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-27576 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-27576?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-27576 can be triaged on real exposure rather than presence alone.

Is CVE-2026-27576 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-27576 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-27576?

CVE-2026-27576 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 7th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-27576?

CVE-2026-27576 is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-27576 published, and has it been updated?

CVE-2026-27576 was published on February 21, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-27576 — openclaw

Fix: openclaw/openclaw@63e39d7

CVE-2026-27576 is a Uncontrolled Resource Consumption vulnerability in openclaw. A fix is available for openclaw — see the affected versions and patch details below.

OpenClaw: ACP prompt-size checks missing in local stdio bridge could reduce responsiveness with very large inputs

Also known asGHSA-cxpw-2g23-2vgw

Published

Feb 21, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27576.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs7th percentile — riskier than 7% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

133other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

openclawnpm

2.5Mdownloads / week

Description

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)

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

Affected Components

src/acp/event-mapper.ts
src/acp/translator.ts

Remediation

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

Fix Commit(s)

732e53151e8fbdfc0501182ddb0e900878bdc1e3
ebcf19746f5c500a41817e03abecadea8655654a
63e39d7f57ac4ad4a5e38d17e7394ae7c4dd0b9c

Thanks @aether-ai-agent for reporting.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`openclaw`	all versions	2026.2.19`npm install openclaw@2026.2.19`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openclaw, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openclaw to 2026.2.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27576 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-27576 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-27576. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## 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) ## Impact - Local ACP sessions may become less responsive when very large prompts are submitted - Larger-than-expected model usage/cost when oversized

O3 Security · Impact-Aware SCA

Is CVE-2026-27576 in your dependencies?

O3 Security finds CVE-2026-27576 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works