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TI-2026-74893 Aliases CVE-2026-109924GHSA-4qv8-2p9j-2685

Unbounded memory in undici EventSource parser allows denial of service

Priority LOW 33CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 2 fixed, 17 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.

Summary

undici versions from 6.5.0 before 6.29.1, from 7.0.0 before 7.30.1, and from 8.0.0 before 8.12.2 are affected. The EventSource parser retains growing per-field and per-chunk state that the byte-based size limits do not bound, which is a case of CWE-770. A malicious or compromised Server-Sent Events peer can exhaust process memory and terminate an application that keeps an EventSource connection open to it, so availability is the only impact.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

undici is an HTTP client library for Node.js. In versions 6.5.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its EventSource client can be driven to exhaust process memory by a malicious or compromised Server-Sent Events peer. By sending millions of tiny completed data fields with no blank event separator, or a single unfinished line split across many chunks, the parser retains a growing amount of per-field and per-chunk state that the byte-based maxEventSize and maxResponseSize limits do not bound, and because maxResponseSize is enforced on the compressed body before decompression, a small compressed response can expand into enough retained memory to terminate the process. An application only needs to maintain an EventSource connection to an untrusted peer, which controls only the response, and availability is the only impact. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which bound the retained parser state independently of the byte limits, and users should upgrade to one of those versions or later. There is no workaround.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00321 25th percentileScored 2026-11-07
Fix Partial undici (undici): 6.29.1, 7.30.1, 8.12.2undici (npm): 6.29.1, 7.30.1, 8.12.2Red Hat: 4 advisoriesRed Hat: 2 fixed, 17 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
NodeJSundici6.5.0 to before 6.29.1; 7.0.0 to before 7.30.1; 8.0.0 to before 8.12.26.29.1, 7.30.1, 8.12.2Patch availableCNA
—undici (npm)6.5.0 to before 6.29.16.29.1Patch availableGHSA-4qv8-2p9j-2685
—undici (npm)7.0.0 to before 7.30.17.30.1Patch availableGHSA-4qv8-2p9j-2685
—undici (npm)8.0.0 to before 8.12.28.12.2Patch availableGHSA-4qv8-2p9j-2685
  • undici VendorNodeJS Affected 6.5.0 to before 6.29.1; 7.0.0 to before 7.30.1; 8.0.0 to before 8.12.2 Fixed in 6.29.1, 7.30.1, 8.12.2 Patch available CNA
  • undici (npm) Vendor— Affected 6.5.0 to before 6.29.1 Fixed in 6.29.1 Patch available GHSA-4qv8-2p9j-2685
  • undici (npm) Vendor— Affected 7.0.0 to before 7.30.1 Fixed in 7.30.1 Patch available GHSA-4qv8-2p9j-2685
  • undici (npm) Vendor— Affected 8.0.0 to before 8.12.2 Fixed in 8.12.2 Patch available GHSA-4qv8-2p9j-2685

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*6.5.0 to before 6.29.1; 7.0.0 to before 7.30.1; 8.0.0 to before 8.12.2VulnerableNodeJS
  • cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:* Versions 6.5.0 to before 6.29.1; 7.0.0 to before 7.30.1; 8.0.0 to before 8.12.2 Vulnerable ·NodeJS

Remediation

Upgrade the undici npm package to 6.29.1, 7.30.1, or 8.12.2, which bound the retained parser state independently of the byte limits. Red Hat advisories RHSA-2026:95124 (Red Hat Trusted Artifact Signer 1.5), RHSA-2026:87703, RHSA-2026:84706, and RHSA-2026:84657 (Red Hat Hardened Images) address this flaw. Red Hat lists Red Hat Enterprise Linux 8, 9, and 10 as affected with no fix available, and Exploit Intelligence with no fix planned.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA undici (undici) Fixed in 6.29.1, 7.30.1, 8.12.2
  • Fix · GHSA-4qv8-2p9j-2685 undici (npm) Fixed in 6.29.1 Advisory →
  • Fix · GHSA-4qv8-2p9j-2685 undici (npm) Fixed in 7.30.1 Advisory →
  • Fix · GHSA-4qv8-2p9j-2685 undici (npm) Fixed in 8.12.2 Advisory →

Red Hat 4 advisories

  • RHSA-2026:95124 Released 2026-11-04 · Red Hat rating Important
    RHTAS 1.5.1 - Red Hat Trusted Artifact Signer Release
    • Red Hat Trusted Artifact Signer 1.5 registry.redhat.io/rhtas/rhtas-console-rhel9, registry.redhat.io/rhtas/rhtas-console-ui-rhel9
  • RHSA-2026:87703 Released 2026-10-22 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images nodejs26-1:26.12.1-0.1.hum1@aarch64, nodejs26-1:26.12.1-0.1.hum1@s390x, nodejs26-1:26.12.1-0.1.hum1@src +22
  • RHSA-2026:84706 Released 2026-10-19 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images nodejs24-24.21.0-1.5.hum1@aarch64, nodejs24-24.21.0-1.5.hum1@s390x, nodejs24-24.21.0-1.5.hum1@src +25
Show 1 more Red Hat advisories
  • RHSA-2026:84657 Released 2026-10-19 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images nodejs26-26.11.1-0.4.hum1@aarch64, nodejs26-26.11.1-0.4.hum1@s390x, nodejs26-26.11.1-0.4.hum1@src +25

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    undici 6.29.1, 7.30.1, 8.12.2

    5 records Highest priority Priority MEDIUM 1 MEDIUM, 4 LOW

    Other records, highest priority first

    • TI-2026-74886 Certificate validation bypass in undici Agent drops custom TLS checksPriority MEDIUM 40
    • TI-2026-74890 Unhandled error in undici fetch() crashes Node.js processPriority LOW 39
    • TI-2026-74992 Denial of service in undici via TLS renegotiationPriority LOW 38
    Show all 5 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Cryostat 4AffectedNo fix yet: Fix deferred
Exploit IntelligenceAffectedNo fix planned: Out of support scope
Red Hat AMQ Broker 7AffectedNo fix yet: Fix deferred
Red Hat Ansible Automation Platform 2AffectedNo fix yet: Fix deferred
Red Hat Build of Podman DesktopAffectedNo fix yet: Fix deferred
Red Hat Developer Hub 1AffectedNo fix yet
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesAffectedNo fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Red Hat OpenShift Dev SpacesAffectedNo fix yet
Red Hat Openshift Data Foundation 4AffectedNo fix yet: Fix deferred
Secrets Management Console for Red Hat OpenShiftAffectedNo fix planned: Out of support scope
Self-service automation portal 2AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:84657, RHSA-2026:84706, RHSA-2026:87703
Red Hat Trusted Artifact Signer 1.5Fixed RHSA-2026:95124
Not affected: 2 products
  • Red Hat Hardened Images
  • Red Hat Trusted Artifact Signer 1.5

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-109924
  2. 2026-10-16 Priority changed: MEDIUM → LOW
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-16 CVSS score added · Red Hat
  5. 2026-10-18 CISA SSVC decision points changed
  6. 2026-10-18 Affected versions changed · Red Hat
  7. 2026-10-19 Fix available: RHSA-2026:84657 · Red Hat
  8. 2026-10-19 Fix available: RHSA-2026:84706 · Red Hat
  9. 2026-10-20 CVSS score added · NVD
  10. 2026-10-20 Fix available: Red Hat Hardened Images · Red Hat
  11. 2026-10-22 Fix available: RHSA-2026:87703 · Red Hat
  12. 2026-10-23 Affected versions changed · Red Hat
  13. 2026-10-23 Alias added: GHSA-4qv8-2p9j-2685
  14. 2026-10-23 Fix available: npm/[email protected], npm/[email protected], npm/[email protected] · GHSA-4qv8-2p9j-2685
  15. 2026-10-23 CVSS score added · GHSA-4qv8-2p9j-2685
  16. 2026-10-23 Weakness changed · GHSA-4qv8-2p9j-2685
  17. 2026-10-23 10 new references · GHSA-4qv8-2p9j-2685
  18. 2026-10-27 Affected versions changed · Red Hat
  19. 2026-10-30 Affected versions changed · Red Hat
  20. 2026-11-04 Fix available: RHSA-2026:95124 · Red Hat
  21. 2026-11-04 Fix available: Red Hat Trusted Artifact Signer 1.5 · Red Hat

References

Advisory 3

Other 7

  • TI-2026-01215 undici is vulnerable to Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') CVSS 3.1CRITICAL 9.8
  • TI-2022-16376 `undici.request` vulnerable to SSRF using absolute URL on `pathname` CVSS 3.1CRITICAL 9.8
  • TI-2023-09734 CRLF Injection in Nodejs ‘undici’ via host CVSS 3.1MEDIUM 6.5
  • TI-2022-13193 CRLF injection in request headers CVSS 3.1MEDIUM 6.5
  • TI-2022-16375 CRLF Injection in Nodejs ‘undici’ via Content-Type CVSS 3.1MEDIUM 5.3
  • TI-2022-13194 Uncleared cookies on cross-host/cross-origin redirect in undici CVSS 3.1MEDIUM 6.5
See all 51 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences