CVE-2026-87018

HIGHPre-NVD 7.57.5
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-10-27. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-102318 (ENISA EUVD) · GHSA-qrxm-fqhp-jwvm (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
7.5
EG Score
7.5HIGHhigh confidence
EG Risk
49
EG Risk 49/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.2%
EPSS %ILE
8th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 15, 2026

Last Modified

October 19, 2026

Advisory Details (2)

Auto-updated Oct 15, 2026
Patch available. Sources: github.
Web page

Security Advisories | OpenJS Foundation CVE Numbering Authority

https://cna.openjsf.org/security-advisories.html
GitHub advisoryMentions a patch (unverified)

undici vulnerable to Denial of Service via TLS 1.2 certificate-changing renegotiation · Advisory · nodejs/undici · GitHub

https://github.com/nodejs/undici/security/advisories/GHSA-qrxm-fqhp-jwvm

Vendor Advisories for CVE-2026-87018(6)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(7)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatnodejs26-main-26.12.1-0.1.hum12026-10-22redhat
redhatnodejs26-main-11.20.0-1.26.11.1.0.5.hum12026-10-20redhat
redhatnodejs24-main-24.21.0-1.5.hum12026-10-19redhat
redhatnodejs26-main-11.20.0-1.26.11.1.0.4.hum12026-10-19redhat
npmundici @ 6.29.1 (fixes >= 4.2.1, < 6.29.1)—ghsa
npmundici @ 7.30.1 (fixes >= 7.0.0, < 7.30.1)—ghsa
npmundici @ 8.12.2 (fixes >= 8.0.0, < 8.12.2)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
undici—
  • 4.2.1 up to 6.29.1: fixed in 6.29.1
  • 7.0.0 up to 7.30.1: fixed in 7.30.1
  • 8.0.0 up to 8.12.2: fixed in 8.12.2
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 30× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  2. 2026-11-01 07:38 UTCGHSA enrichmentGHSA-qrxm-fqhp-jwvm · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-11-01 07:38 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  5. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  6. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  7. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  8. 2026-10-27 19:51 UTCEG score recompute
  9. 2026-10-27 19:51 UTCVendor advisory
  10. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  11. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  12. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  13. 2026-10-25 13:54 UTCEG score recompute
  14. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  16. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  17. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  19. 2026-10-19 20:47 UTCEG score recompute
  20. 2026-10-19 20:47 UTCVendor advisory
  21. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  22. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  23. 2026-10-18 03:04 UTCEG score recompute
  24. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  25. 2026-10-16 20:33 UTCEG score recompute
Show 5 more
  1. 2026-10-16 20:10 UTCEG score recompute
  2. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  3. 2026-10-15 19:32 UTCEG score recompute
  4. 2026-10-15 18:44 UTCEG score recomputeFirst assessed: 7.5 HIGH
  5. 2026-10-15 18:42 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-87018?
CVE-2026-87018 is a high-severity vulnerability; its CVE record was published on October 15, 2026. 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…
When was the CVE record for CVE-2026-87018 published?
The CVE record for CVE-2026-87018 was published on October 15, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-87018 actively exploited?
CVE-2026-87018 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-87018?
CVE-2026-87018 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-87018?
A fix for CVE-2026-87018 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-87018 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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