fast-uri is a URI parser for Node.js. It canonicalizes a host to its ASCII form only when the input carries an explicit scheme, so a scheme-relative reference such as a host preceded by two slashes is returned with its host verbatim and no error set. As a result fast-uri's own entry points disagree with each other: parse, resolve, normalize, and equal can yield different hosts for the same input depending only on whether a scheme is written out, and equal can return opposite verdicts for the same pair of hosts. An application that extracts a host with fast-uri to check it against a policy list and then resolves the same reference can make its decision on one host while the destination is another, enabling host confusion and policy bypass. The affected versions are 2.4.2 up to but not including 2.4.5, 3.1.3 up to but not including 3.1.6, and 4.0.1 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which canonicalize the host consistently across the resolve path. Users should upgrade to a patched version.
CVE-2026-75931
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 86% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 14%
- KEV
- Not listed
Published
August 24, 2026
Last Modified
September 2, 2026
Advisory Details (2)
Auto-updated Aug 24, 2026Security Advisories | OpenJS Foundation CVE Numbering Authority
https://cna.openjsf.org/security-advisories.htmlfast-uri vulnerable to host confusion via skipped IDN canonicalization on scheme-relative references · Advisory · fastify/fast-uri · GitHub
https://github.com/fastify/fast-uri/security/advisories/GHSA-5jgf-p345-68v8Vendor Advisories for CVE-2026-75931(7)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:65155Red Hat Product SecurityHigh
Red Hat Security Advisory: Ansible plug-ins for Red Hat Developer Hub Product Release Update
- RHSA-2026:65118Red Hat Product SecurityHigh
Red Hat Security Advisory: Ansible plug-ins for Red Hat Developer Hub Product Release Update
- GHSA-5jgf-p345-68v8GitHub Security AdvisoriesHigh
fast-uri vulnerable to host confusion via skipped IDN canonicalization on scheme-relative references
- RHSA-2026:61783Red Hat Product SecurityHigh
Red Hat Security Advisory: A Subscription Management tool for finding and reporting Red Hat product usage
- RHSA-2026:60866Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:60856Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:60855Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Patch Availability(6)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | ansible-automation-platform/automation-portal:1788775748 | 2026-09-08 | redhat |
| redhat | ansible-automation-platform/automation-portal:1788783591 | 2026-09-08 | redhat |
| redhat | discovery/discovery-ui-rhel9:1788206196 | 2026-08-31 | redhat |
| redhat | grafana13-1-main-13.1.3-0.3.hum1 | 2026-08-29 | redhat |
| redhat | grafana13-2-main-13.2.0-0.1.2.hum1 | 2026-08-29 | redhat |
| redhat | grafana12-4-main-12.4.9-0.4.hum1 | 2026-08-29 | redhat |
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
(3 across 3 ecosystems)
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| node-ajv | 8.12.0~ds+~2.1.1-5 ... 8.20.0~ds+~cs7.1.5-1 (14 versions) | — | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| node-ajv | 8.12.0~ds+~2.1.1-5 ... 8.20.0~ds+~cs7.1.3-3 (12 versions) | 8.20.0~ds+~cs7.1.4-1 | — |
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| fast-uri | — | 4.1.3 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 26× in last 7d / 92× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.
- 2026-09-19 00:35 UTCEG score recompute
- 2026-09-19 00:35 UTCVendor advisory
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 13:19 UTCVendor advisory
- 2026-09-18 02:03 UTCEG score recompute
- 2026-09-18 02:03 UTCVendor advisory
- 2026-09-17 14:46 UTCVendor advisory
- 2026-09-17 03:28 UTCVendor advisory
- 2026-09-16 16:12 UTCEG score recompute
- 2026-09-16 16:12 UTCVendor advisory
- 2026-09-16 14:08 UTCEPSS rescore
- 2026-09-16 05:15 UTCEPSS rescore
- 2026-09-16 04:55 UTCVendor advisory
- 2026-09-15 17:38 UTCVendor advisory
- 2026-09-15 06:22 UTCEG score recompute
- 2026-09-15 06:22 UTCVendor advisory
- 2026-09-15 03:12 UTCEPSS rescore
- 2026-09-14 19:04 UTCVendor advisory
- 2026-09-14 07:47 UTCVendor advisory
- 2026-09-13 20:30 UTCEG score recompute
- 2026-09-13 20:30 UTCVendor advisory
- 2026-09-13 09:13 UTCVendor advisory
- 2026-09-12 21:57 UTCEG score recompute
- 2026-09-12 21:57 UTCVendor advisory
- 2026-09-12 15:02 UTCEPSS rescore
Show 67 moreShow fewer
- 2026-09-12 10:41 UTCVendor advisory
- 2026-09-11 23:24 UTCEG score recompute
- 2026-09-11 23:24 UTCVendor advisory
- 2026-09-11 14:53 UTCEPSS rescore
- 2026-09-11 12:03 UTCEG score recompute
- 2026-09-11 12:03 UTCVendor advisory
- 2026-09-11 00:15 UTCVendor advisory
- 2026-09-10 12:10 UTCEG score recompute
- 2026-09-10 12:10 UTCVendor advisory
- 2026-09-10 09:35 UTCEPSS rescore
- 2026-09-10 00:37 UTCVendor advisory
- 2026-09-09 12:54 UTCVendor advisory
- 2026-09-09 01:34 UTCEG score recompute
- 2026-09-09 01:34 UTCVendor advisory
- 2026-09-08 22:01 UTCEPSS rescore
- 2026-09-08 06:56 UTCVendor advisory
- 2026-09-07 19:31 UTCEG score recompute
- 2026-09-07 19:31 UTCVendor advisory
- 2026-09-07 08:14 UTCVendor advisory
- 2026-09-06 20:58 UTCEG score recompute
- 2026-09-06 20:58 UTCVendor advisory
- 2026-09-06 13:48 UTCEPSS rescore
- 2026-09-06 09:41 UTCVendor advisory
- 2026-09-05 22:25 UTCEG score recompute
- 2026-09-05 22:25 UTCVendor advisory
- 2026-09-05 11:07 UTCVendor advisory
- 2026-09-04 23:45 UTCEG score recompute
- 2026-09-04 23:45 UTCVendor advisory
- 2026-09-04 12:12 UTCEG score recompute
- 2026-09-04 12:12 UTCVendor advisory
- 2026-09-04 05:07 UTCEPSS rescore
- 2026-09-04 00:55 UTCVendor advisory
- 2026-09-03 13:38 UTCVendor advisory
- 2026-09-03 02:20 UTCVendor advisory
- 2026-09-02 15:01 UTCEG score recompute
- 2026-09-02 15:01 UTCVendor advisory
- 2026-09-02 14:12 UTCEPSS rescore
- 2026-09-02 03:46 UTCVendor advisory
- 2026-09-01 16:29 UTCEG score recompute
- 2026-09-01 16:29 UTCVendor advisory
- 2026-09-01 13:54 UTCEPSS rescore
- 2026-09-01 05:08 UTCEG score recompute
- 2026-09-01 05:08 UTCVendor advisory
- 2026-09-01 04:40 UTCEPSS rescore
- 2026-09-01 04:40 UTCEPSS rescore
- 2026-08-31 17:51 UTCVendor advisory
- 2026-08-31 04:32 UTCEG score recompute
- 2026-08-31 04:32 UTCVendor advisory
- 2026-08-30 19:18 UTCEPSS rescore
- 2026-08-30 19:17 UTCEPSS rescore
- 2026-08-30 17:15 UTCVendor advisory
- 2026-08-30 05:59 UTCEG score recompute
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-29 07:20 UTCEG score recompute
- 2026-08-28 21:42 UTCEPSS rescore
- 2026-08-28 00:24 UTCEG score recompute
- 2026-08-27 14:25 UTCEPSS rescore
- 2026-08-27 01:43 UTCEG score recompute
- 2026-08-26 14:47 UTCEPSS rescore
- 2026-08-25 15:52 UTCEG score recompute
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-24 17:19 UTCEG score recompute
- 2026-08-24 16:35 UTCEG score recompute
- 2026-08-24 14:18 UTCEPSS rescore
- 2026-08-24 10:24 UTCEG score recompute
- 2026-08-24 09:43 UTCEG score recompute
- 2026-08-24 09:42 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-75931?
When was CVE-2026-75931 disclosed?
Is CVE-2026-75931 actively exploited?
What is the CVSS score of CVE-2026-75931?
How do I remediate CVE-2026-75931?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-75931
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