7.5

CVE-2026-75975: fast-uri vulnerable to server-side request forgery via malformed IPv6 normalization

Analyzed
AliasesUBUNTU-CVE-2026-75975DEBIAN-CVE-2026-75975CGA-22vp-vfqw-55h9
Published 24-08-2026Last modified 24-08-2026

Vulnerability summary

CVE-2026-75975 is a high (CVSS 7.5) Improper Input Validation vulnerability in fast-uri. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.6% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.22%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 1
RHSA-2026:60855RHSA-2026:60856RHSA-2026:60866RHSA-2026:71543RHSA-2026:74503CGA-HW9P-V29W-G2VX

Timeline

  1. 24-08-2026
    PublishedVulnerability first disclosed.
  2. 24-08-2026
    Last modifiedVulnerability information updated.

Description

fast-uri is a URI parser for Node.js. Its custom parser for bracketed IPv6 literals does not validate the complete IPv6 grammar, so invalid trailing text in an authority can be silently discarded and a malformed attacker-controlled host is turned into a different valid IPv6 destination. For example, a bracketed literal with invalid trailing characters is normalized to the unspecified address, which a Node HTTP client then connects to a local service over loopback, and other malformed literals collapse to private-range addresses. No error is set on the parsed result, so an application checking the error field cannot detect the rewrite. An application that normalizes untrusted URLs before outbound requests, redirects, proxy routing, or address-policy enforcement can be redirected to a local or private IPv6 target, giving a server-side request forgery and address-policy bypass primitive. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 up to but not including 3.1.6, and 4.0.0 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which validate bracketed IP literals against the full grammar and mark malformed literals as authority errors. Users should upgrade to a patched version.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.22% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard94 products
  • airflow-2All versions (No fix recorded)
  • airflow-core-2All versions (No fix recorded)
  • arangodb-3.12< 3.12.11-r1
  • argo-workflows-ui-4.0< 4.0.11-r0
  • commercial-gitlab-rails-ee-19.1< 19.1.7-r3
Wolfi21 products
  • argo-workflows-ui-4.0< 4.0.11-r0
  • jupyter-base-notebook< 7.6.3-r2
  • nextcloud-server-32< 32.0.14-r1
  • opensearch-dashboards-3< 3.8.0-r1
  • opensearch-dashboards-3-alerting-dashboards-plugin< 3.8.0-r1
Debian1 product
  • node-ajvAll versions (No fix recorded) | < 8.20.0~ds+~cs7.1.4-1
Fast-uri1 product
  • fast-uri≥ 2.3.1, < 2.4.5 | ≥ 3.0.0, < 3.1.6 | ≥ 4.0.0, < 4.1.3
Npm1 product
  • fast-uri≥ 2.3.1, < 2.4.5 | ≥ 3.0.0, < 3.1.6 | ≥ 4.0.0, < 4.1.3
Openjsf1 product
  • fast-uri≥ 2.3.1, < 2.4.5 | ≥ 3.0.0, < 3.1.6 | ≥ 4.0.0, < 4.1.3
Ubuntu1 product
  • node-ajvAll versions (No fix recorded)

7 vendors · 120 products

References

14 links
Show all 14 references