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No exploitation reportedFix available

CVE-2026-109932

undici WebSocket client vulnerable to Denial of Service via unbounded automatic PONG buffering

No exploitation reported by the sources we read.

  • Published2026-10-15
  • Fixed in8.12.2 · 7.30.1 · 6.29.1
  • WeaknessCWE-400 · CWE-405 · CWE-770

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

undici is an HTTP client library for Node.js. In versions 5.15.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its WebSocket client, including the bundled WebSocket exposed by Node.js, can be driven to exhaust process memory by a malicious or compromised WebSocket server. For every PING frame received, the client automatically writes a PONG response and ignores the backpressure signal from the socket write, so a server that streams small PING frames while never reading the client's PONGs makes the outbound write queue and heap grow without bound until the Node.js process runs out of memory and terminates. The attack is remote and unauthenticated, needs only a normal WebSocket connection, and is asymmetric, since small inbound PINGs produce a much larger retained outbound queue, with availability the only impact. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which pause WebSocket frame parsing when the automatic PONG response hits socket backpressure and resume on drain, bounding the outbound queue, and users should upgrade to one of those versions or later. There is no workaround.

Timeline

dates in UTC
  1. 2026-10-1519:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-109932?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-109932?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Nodejs undici
BranchAffectedFixed in
8.x≥ 8.0.0, < 8.12.28.12.2
7.x≥ 7.0.0, < 7.30.17.30.1
6.29≥ 5.15.0, < 6.29.16.29.1

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2026-109932 Red Hat Product Security81 products fixed · 113 known affected

    undici: undici: Denial of Service via unbounded WebSocket PONG buffering

    cryostat/cryostat-openshift-console-plugin-rhel9 as a component of Cryostat 4 · exploit-intelligence/vulnerability-analysis-rhel9 as a component of Exploit Intelligence · amq-broker-bin.zip as a component of Red Hat AMQ Broker 7 · +110 more

  • RHSA-2026:87703 Red Hat Product Security25 products fixed

    Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

  • RHSA-2026:84706 Red Hat Product Security28 products fixed

    Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

  • RHSA-2026:84657 Red Hat Product Security28 products fixed

    Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

Full record on NVD

Fix

  1. Update Nodejs undici to 8.12.2 · 7.30.1 · 6.29.1
  2. Vendor fix Red Hat Product Security RHSA-2026:87703 · 25 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-109932 · 100 productsFix deferred
  4. No fix available, says the vendor Red Hat Product Security CVE-2026-109932 · 10 productsAffected
  5. No fix planned, says the vendor Red Hat Product Security CVE-2026-109932 · 2 productsOut of support scope
  6. No fix planned, says the vendor Red Hat Product Security CVE-2026-109932 · 1 productWill not fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2026-10-16
  • OpenCVESSVC decisionnone—
  • CNACVSS 3.15.9read 2026-10-23
  • NVDCVSS 3.17.5read 2026-10-23
  • CNAweakness (CWE)CWE-400, CWE-405, CWE-770read 2026-10-23
  • FIRST EPSSEPSS score0.3 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-10-15
Last Modified
2026-10-19
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-109932?

undici is an HTTP client library for Node.js. In versions 5.15.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its WebSocket client, including the bundled WebSocket exposed by Node.js, can be driven to exhaust process memory by a malicious or compromised WebSocket server. For every PING frame received, the client automatically writes a PONG response and ignores the backpressure signal from the socket write, so a server that streams small PING frames while never reading the client's PONGs makes the outbound write queue and heap grow without bound until the Node.js process runs out of memory and terminates. The attack is remote and unauthenticated, needs only a normal WebSocket connection, and is asymmetric, since small inbound PINGs produce a much larger retained outbound queue, with availability the only impact. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which pause WebSocket frame parsing when the automatic PONG response hits socket backpressure and resume on drain, bounding the outbound queue, and users should upgrade to one of those versions or later. There is no workaround.

Is CVE-2026-109932 actively exploited?

Active exploitation of CVE-2026-109932 has not been confirmed. Its EPSS score was 0.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-109932?

CVE-2026-109932 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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