CVE-2026-109829

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.1% (3rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — Patch released this week
9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

undici is an HTTP client library for Node.js. In versions 7.0.0 through 7.30.0 and 8.0.0 through 8.12.1, when an originless Agent composes the redirect and cache interceptors in that order with a shared cache store, the cache builds its key from the original request URL before the redirect handler changes the origin, so a response produced after a cross-origin redirect is stored under the original key. An attacker who controls the target of a redirect from a trusted URL can have their response cached under that trusted URL and served to later callers, allowing persistent cache poisoning, and the same key confusion lets a private, non-stored redirect response to a user-specific resource be stored under the original URL and served to a later unauthenticated caller, disclosing private data. Applications are affected only when an originless Agent, a shared cache store, and the redirect-then-cache composition are all used. The issue is fixed in undici 7.30.1 and 8.12.2, which verify the producing origin still matches the cache key and preserve each redirect hop's cache-control policy before storing, and users should upgrade to one of those versions or later. As a workaround, compose the cache interceptor before the redirect interceptor, use per-origin dispatchers and cache stores, or disable shared caching on redirect-capable requests.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
41
EG Risk 41/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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.
EPSS PROB
0.1%
EPSS %ILE
3rd
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-21). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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 cache poisoning and cross-user disclosure via cross-origin redirects · Advisory · nodejs/undici · GitHub

https://github.com/nodejs/undici/security/advisories/GHSA-4w7w-5xrc-9h26

Vendor Advisories for CVE-2026-109829(2)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatnodejs26-main-26.11.1-0.4.hum12026-10-19redhat
redhatnodejs24-main-24.21.0-1.5.hum12026-10-19redhat

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.

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 19× 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. 2026-10-21 22:46 UTCEG score recompute
  2. 2026-10-21 22:46 UTCVendor advisory
  3. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  4. 2026-10-20 21:58 UTCEG score recompute
  5. 2026-10-20 21:58 UTCVendor advisory
  6. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  7. 2026-10-19 21:09 UTCEG score recompute▲ 1.70
  8. 2026-10-19 21:09 UTCVendor advisory
  9. 2026-10-19 21:05 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  10. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  11. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  12. 2026-10-18 05:06 UTCEG score recompute
  13. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  14. 2026-10-16 21:27 UTCEG score recompute
  15. 2026-10-16 20:23 UTCEG score recompute
  16. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.1% · 3rd percentile
  17. 2026-10-15 19:32 UTCEG score recompute
  18. 2026-10-15 18:44 UTCEG score recomputeFirst assessed: 7.4 HIGH
  19. 2026-10-15 18:42 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-109829?
CVE-2026-109829 is a critical-severity vulnerability; its CVE record was published on October 15, 2026. undici is an HTTP client library for Node.js. In versions 7.0.0 through 7.30.0 and 8.0.0 through 8.12.1, when an originless Agent composes the redirect and cache interceptors in that order with a shared cache store, the cache builds its key from the original request URL before the redirect handler…
When was the CVE record for CVE-2026-109829 published?
The CVE record for CVE-2026-109829 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-2026-109829 actively exploited?
CVE-2026-109829 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (3rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-109829?
CVE-2026-109829 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-109829?
A fix for CVE-2026-109829 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-109829 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-109829

Explore →

Is Your Infrastructure Affected by CVE-2026-109829?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs