undici is an HTTP client library for Node.js. In versions 7.15.0 through 7.30.0 and 8.0.0 through 8.12.1, its fetch() implementation verifies Subresource Integrity metadata by matching the algorithm token against a lowercase-only set, even though the SRI specification defines the token by its ASCII-lowercase form, so a valid but non-lowercase token such as an uppercase or mixed-case SHA256 is treated as unknown and skipped. When no recognized algorithm remains, undici treats the integrity list as empty and accepts the response, so a server returning a body that does not match the pinned digest passes the check. An attacker who controls only the response body can therefore deliver attacker-controlled bytes to an application that pinned a valid uppercase or mixed-case SRI token, with no integrity error, affecting response integrity only. The issue is fixed in undici 7.30.1 and 8.12.2, which normalize the algorithm token to ASCII lowercase before validation, and users should upgrade to one of those versions or later. As a workaround, use lowercase algorithm tokens such as sha256, sha384, or sha512 in integrity metadata.
CVE-2026-109841
“▼” beside the score: it is lower than NVD's CVSS score.
Score 5.9 from GitHub Security Advisory (severity: MODERATE) published 2026-10-23. NVD baseline CVSS 7.5; sources differ by 1.6.
Also known asEUVD-2026-102305 (ENISA EUVD) · GHSA-f72v-6w45-q472 (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 5.9MEDIUMmedium confidence
- EG Risk
- 27EG Risk 27/100
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)Severity59% × 45%Impact severity (EG Severity): CVSS 5.9 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.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (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. - EPSS PROB
- 0.3%
- EPSS %ILE
- 16th
- 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 (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.3% 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade 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 every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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, 2026Security Advisories | OpenJS Foundation CVE Numbering Authority
https://cna.openjsf.org/security-advisories.htmlundici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens · Advisory · nodejs/undici · GitHub
https://github.com/nodejs/undici/security/advisories/GHSA-f72v-6w45-q472Vendor Advisories for CVE-2026-109841(3)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- GHSA-f72v-6w45-q472GitHub Security AdvisoriesMedium
undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens
- RHSA-2026:84706Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:84657Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Patch Availability(4)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | nodejs26-main-26.11.1-0.4.hum1 | 2026-10-19 | redhat |
| redhat | nodejs24-main-24.21.0-1.5.hum1 | 2026-10-19 | redhat |
| npm | undici @ 7.30.1 (fixes >= 7.15.0, < 7.30.1) | — | ghsa |
| npm | undici @ 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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| undici | — |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 31× 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.
- 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-11-01 08:00 UTCGHSA enrichmentGHSA-f72v-6w45-q472 · GitHub severity MODERATE · GitHub CVSS 5.9
- 2026-11-01 08:00 UTCEG score recompute▼ 1.60
- 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-27 18:22 UTCEG score recompute
- 2026-10-27 18:22 UTCVendor advisory
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 16th percentile
- 2026-10-25 14:53 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 15th percentile
- 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
- 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
- 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
- 2026-10-19 21:10 UTCEG score recompute▲ 1.60
- 2026-10-19 21:10 UTCVendor advisory
- 2026-10-19 21:05 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
- 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-18 05:06 UTCEG score recompute
- 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
Show 6 moreShow fewer
- 2026-10-16 21:45 UTCEG score recompute
- 2026-10-16 20:23 UTCEG score recompute
- 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-15 19:36 UTCEG score recompute
- 2026-10-15 18:44 UTCEG score recomputeFirst assessed: 5.9 MEDIUM
- 2026-10-15 18:42 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownnpm:undici
Same vendor
8 shownredhat:RHSA-2026:84657
Frequently asked(5)
What is CVE-2026-109841?
When was the CVE record for CVE-2026-109841 published?
Is CVE-2026-109841 actively exploited?
What is the CVSS score of CVE-2026-109841?
How do I remediate CVE-2026-109841?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-109841
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