Read the docs
TI-2026-74992 Aliases CVE-2026-87018GHSA-qrxm-fqhp-jwvm

Denial of service in undici via TLS renegotiation

Priority LOW 38CWE-248Published · 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: 4 fixed, 15 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-248.

Summary

undici, an HTTP client library for Node.js, is affected from 4.2.1 before 6.29.1, from 7.0.0 before 7.30.1, and from 8.0.0 before 8.12.2. An assertion in undici's socket error handler (CWE-617) turns a hostname mismatch during TLS 1.2 renegotiation into an uncaught exception. A malicious HTTPS endpoint can crash the client with one renegotiation presenting a different valid certificate. TLS 1.3 is not affected.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

undici is an HTTP client library for Node.js. In versions 4.2.1 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, the client process crashes when a TLS 1.2 server renegotiates after the connection is established and presents a different, CA-trusted certificate whose hostname does not match the requested host. Node.js re-runs hostname verification on the renegotiated handshake and destroys the socket with a certificate-altname error, but undici's established-socket error handler asserted that this error code could never occur, so the peer-controlled error became an uncaught assertion that terminates the Node.js process, affecting both the HTTP/1.1 and HTTP/2 paths. A malicious or compromised HTTPS endpoint reached through undici or the global fetch() can crash the client with a single server-initiated renegotiation, taking down all in-flight requests and background work in the process, and exploitation needs no CA compromise because the attacker controls the endpoint and can present two ordinary valid certificates. Only TLS 1.2 is affected, since TLS 1.3 does not support renegotiation. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, and users should upgrade to one of those versions or later. As a workaround, restrict outbound connections to TLS 1.3 so renegotiation cannot occur, when the target endpoints support it.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00187 8th 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: 8 advisoriesRed Hat: 4 fixed, 15 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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
NodeJSundici4.2.1 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)4.2.1 to before 6.29.16.29.1Patch availableGHSA-qrxm-fqhp-jwvm
—undici (npm)7.0.0 to before 7.30.17.30.1Patch availableGHSA-qrxm-fqhp-jwvm
—undici (npm)8.0.0 to before 8.12.28.12.2Patch availableGHSA-qrxm-fqhp-jwvm
  • undici VendorNodeJS Affected 4.2.1 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 4.2.1 to before 6.29.1 Fixed in 6.29.1 Patch available GHSA-qrxm-fqhp-jwvm
  • undici (npm) Vendor— Affected 7.0.0 to before 7.30.1 Fixed in 7.30.1 Patch available GHSA-qrxm-fqhp-jwvm
  • undici (npm) Vendor— Affected 8.0.0 to before 8.12.2 Fixed in 8.12.2 Patch available GHSA-qrxm-fqhp-jwvm

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*4.2.1 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 4.2.1 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 undici to 6.29.1, 7.30.1 or 8.12.2 or later. Red Hat fixes are in RHSA-2026:95591, RHSA-2026:95081, RHSA-2026:95124, RHSA-2026:92510, RHSA-2026:87703, RHSA-2026:86147, RHSA-2026:84706 and RHSA-2026:84657. Red Hat lists no available fix for Red Hat Enterprise Linux 8, 9 and 10 and other affected products. Until upgrading, restrict outbound connections to TLS 1.3 where the target endpoints support it.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA undici (undici) Fixed in 6.29.1, 7.30.1, 8.12.2
  • Fix · GHSA-qrxm-fqhp-jwvm undici (npm) Fixed in 6.29.1 Advisory →
  • Fix · GHSA-qrxm-fqhp-jwvm undici (npm) Fixed in 7.30.1 Advisory →
  • Fix · GHSA-qrxm-fqhp-jwvm undici (npm) Fixed in 8.12.2 Advisory →

Red Hat 8 advisories

  • RHSA-2026:95591 Released 2026-11-05 · Red Hat rating Important
    Cluster Observability Operator - 1.5
    • Cluster Observability Operator 1.5 registry.redhat.io/cluster-observability-operator/alertmanager-rhel9, registry.redhat.io/cluster-observability-operator/cluster-observability-rhel9-operator, registry.redhat.io/cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9 +16
  • 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-2026:95081 Released 2026-11-04 · Red Hat rating Important
    Cluster Observability Operator - 1.5
    • Cluster Observability Operator 1.5 registry.redhat.io/cluster-observability-operator/alertmanager-rhel9, registry.redhat.io/cluster-observability-operator/cluster-observability-rhel9-operator, registry.redhat.io/cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9 +16
Show 5 more Red Hat advisories
  • RHSA-2026:92510 Released 2026-10-29 · Red Hat rating Critical
    RHOAI 3.4.6 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-cli-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47
  • 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-2026:86147 Released 2026-10-20 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images nodejs26-26.11.1-0.5.hum1@aarch64, nodejs26-26.11.1-0.5.hum1@s390x, nodejs26-26.11.1-0.5.hum1@src +25
  • 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
  • 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-2026-74894 Undici WebSocket client exhausts memory via unbounded PONG bufferingPriority LOW 33
    Show all 5 records →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Exploit IntelligenceAffectedNo fix yet
Red Hat AMQ Broker 7AffectedNo fix yet
Red Hat Build of Podman DesktopAffectedNo fix yet
Red Hat Developer Hub 1AffectedNo fix yet
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat Hardened ImagesAffectedNo fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat OpenShift Dev SpacesAffectedNo fix yet
Red Hat Openshift Data Foundation 4AffectedNo fix yet
Secrets Management Console for Red Hat OpenShiftAffectedNo fix planned: Will not fix
Self-service automation portal 2AffectedNo fix yet
Cluster Observability Operator 1.5Fixed RHSA-2026:95081, RHSA-2026:95591
Red Hat Hardened ImagesFixed RHSA-2026:84657, RHSA-2026:84706, RHSA-2026:86147, RHSA-2026:87703
Red Hat OpenShift AI 3.4Fixed RHSA-2026:92510
Red Hat Trusted Artifact Signer 1.5Fixed RHSA-2026:95124
Not affected: 8 products
  • Cluster Observability Operator 1.5
  • Cryostat 4
  • Red Hat AMQ Broker 7
  • Red Hat Ansible Automation Platform 2
  • Red Hat Enterprise Linux 10
  • Red Hat Hardened Images
  • Red Hat OpenShift AI 3.4
  • Red Hat Trusted Artifact Signer 1.5

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-87018
  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 Fix available: Red Hat Hardened Images · Red Hat
  10. 2026-10-21 Fix available: RHSA-2026:86147 · Red Hat
  11. 2026-10-21 Affected versions changed · Red Hat
  12. 2026-10-22 Fix available: RHSA-2026:87703 · Red Hat
  13. 2026-10-23 Affected versions changed · Red Hat
  14. 2026-10-27 Affected versions changed · Red Hat
  15. 2026-10-27 Alias added: GHSA-qrxm-fqhp-jwvm
  16. 2026-10-30 Fix available: RHSA-2026:92510 · Red Hat
  17. 2026-10-30 Fix available: Red Hat OpenShift AI 3.4 · Red Hat
  18. 2026-10-30 Affected versions changed · Red Hat
  19. 2026-11-04 Fix available: RHSA-2026:95081 · Red Hat
  20. 2026-11-04 Fix available: RHSA-2026:95124 · Red Hat
  21. 2026-11-04 Fix available: Cluster Observability Operator 1.5, Red Hat Trusted Artifact Signer 1.5 · Red Hat
  22. 2026-11-06 Affected versions changed · Red Hat
  23. 2026-11-06 Fix available: RHSA-2026:95591 · 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