How severe is GHSA-qq8j-7v2v-3rwp?

GHSA-qq8j-7v2v-3rwp has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-qq8j-7v2v-3rwp?

GHSA-qq8j-7v2v-3rwp affects the following packages: undici (npm). Ecosystems affected: npm.

How do I fix GHSA-qq8j-7v2v-3rwp?

Update undici to 8.11.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qq8j-7v2v-3rwp is resolved across your whole dependency graph.

How do I detect GHSA-qq8j-7v2v-3rwp in my npm dependencies?

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

How do I mitigate GHSA-qq8j-7v2v-3rwp 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.

Is GHSA-qq8j-7v2v-3rwp actively exploited in the wild?

No public exploit code has been indexed for GHSA-qq8j-7v2v-3rwp 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 GHSA-qq8j-7v2v-3rwp?

GHSA-qq8j-7v2v-3rwp has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 20th 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 GHSA-qq8j-7v2v-3rwp?

GHSA-qq8j-7v2v-3rwp is classified as CWE-248 (CWE-248), CWE-754 (CWE-754). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-qq8j-7v2v-3rwp published, and has it been updated?

GHSA-qq8j-7v2v-3rwp was published on October 27, 2026 and was last updated on October 27, 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

HIGH severity

undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshakeGHSA-qq8j-7v2v-3rwp

HIGHFix: nodejs/undici#5873

GHSA-qq8j-7v2v-3rwp is a high-severity (CVSS 7.5) CWE-248 vulnerability in undici. A fix is available for undici — see the affected versions and patch details below.

Also known asCVE-2026-109855

Published

Oct 27, 2026

Updated

Oct 27, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 27, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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 GHSA-qq8j-7v2v-3rwp.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs20th percentile — riskier than 20% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-qq8j-7v2v-3rwp by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 396,966 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

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.

9Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

undicinpm

201.8Mdownloads / week

Description

Impact

undici's experimental WebSocket client (enabled by default via allowH2: true) crashes the Node.js process when it connects to a malicious server over HTTP/2. If the server answers the WebSocket upgrade with a response that fails handshake validation, undici aborts the request, but the abort is a no-op because the request is already marked completed, so the underlying ClientHttp2Stream is left open with no error listener. When the server then destroys the connection, the orphaned stream emits an unhandled error and the process exits. A remote, unauthenticated server can therefore deny service to any client that opens a WebSocket to it over HTTP/2. undici 8.11.0 and 8.11.1 are affected; the regression was introduced in 8.11.0.

Patches

Upgrade to 8.11.2.

Workarounds

Set allowH2: false to disable HTTP/2 for WebSocket connections, or avoid opening WebSocket connections to untrusted servers, until upgrading.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`undici`	≥ 8.11.0&&< 8.11.2	8.11.2`npm install undici@8.11.2`

Affected Products

1 product · 1 configurations

Application

undicinodejs

≥ 8.11.0 && < 8.11.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for undici, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update undici to 8.11.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qq8j-7v2v-3rwp 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.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

Product	Fixed in	Advisory
Red Hat Hardened Images	`grafana12-4-main-12.4.12-0.4.hum1`	RHSA-2026:76677
Red Hat Hardened Images	`nodejs26-main-11.20.0-1.26.11.1.0.3.hum1`	RHSA-2026:83198

Frequently Asked Questions

### Impact undici's experimental WebSocket client (enabled by default via `allowH2: true`) crashes the Node.js process when it connects to a malicious server over HTTP/2. If the server answers the WebSocket upgrade with a response that fails handshake validation, undici aborts the request, but the abort is a no-op because the request is already marked completed, so the underlying `ClientHttp2Stream` is left open with no error listener. When the server then destroys the connection, the orphaned stream emits an unhandled `error` and the process exits. A remote, unauthenticated server can theref