CVE-2026-75899
Vulnerability Summary
Timeline
Description
fast-uri is a URI parser for Node.js. It decodes percent escapes in a hostname during parsing and then decodes the parsed hostname a second time during authority recomposition, so a single call to normalize or resolve can turn nested percent-encoded input into a different network destination such as a loopback hostname or address. For example, a doubly encoded host that spells out a loopback name decodes to that live host in one operation, which contradicts RFC 3986 section 2.4 that an implementation must not decode the same string more than once. An application that normalizes or resolves an untrusted HTTP-family URI before outbound routing, redirect validation, or a host-policy check can receive a destination different from the one the original encoded host represented, giving a server-side request forgery and host-policy bypass primitive. This is an incomplete-fix variant of CVE-2026-6322. The affected versions are 2.4.1 up to but not including 2.4.5, 3.1.2 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 normalize percent escapes once and preserve encoded percent signs. Users should upgrade to a patched version.
CVSS Metrics
- v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Trends
Current EPSS score: 0.22%• Percentile: 13%
Techniques & Countermeasures
- CWE-174•Double Decoding of the Same Data
The product decodes the same input twice, which can limit the effectiveness of any protection mechanism that occurs in between the decoding operations.
- CWE-918•Server-Side Request Forgery (SSRF)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Affected Systems
- chainguard•arangodb-3.12
all | < 3.12.11-r1
- chainguard•argo-workflows-ui-4.0
< 4.0.11-r0
- chainguard•gitlab-rails-ce-fips-19.1
< 19.1.7-r5
- chainguard•jupyter-base-notebook
all
- chainguard•keep-ui
< 0.54.2-r8
- chainguard•keep-ui-fips
< 0.54.2-r11
- chainguard•kibana-9.2
< 9.2.8-r20
- chainguard•kibana-9.2-iamguarded
< 9.2.8-r20
- chainguard•kibana-9.3
all | < 9.3.8-r3
- chainguard•kibana-9.3-iamguarded
all
- chainguard•langfuse-4
< 4.27.0-r1
- chainguard•langfuse-4-worker
< 4.27.0-r1
- chainguard•langfuse-fips-4
< 4.26.0-r1
- chainguard•langfuse-fips-4-worker
< 4.26.0-r1
- chainguard•nextcloud-server-32
< 32.0.14-r1
- chainguard•nextcloud-server-34
< 34.0.3-r3
- chainguard•opensearch-dashboards-2
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-alerting-dashboards-plugin
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-anomaly-detection-dashboards-plugin
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-maps
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-notifications
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-observability
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-query-workbench
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-reporting
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-search-relevance
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-dashboards-visualizations
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-fips
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-alerting-dashboards-plugin
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-anomaly-detection-dashboards-plugin
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-maps
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-notifications
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-observability
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-query-workbench
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-reporting
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-search-relevance
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-dashboards-visualizations
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-index-management-dashboards-plugin
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-ml-commons-dashboards
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-security-analytics-dashboards-plugin
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-fips-security-dashboards-plugin
< 2.19.6-r5
- chainguard•opensearch-dashboards-2-index-management-dashboards-plugin
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-ml-commons-dashboards
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-security-analytics-dashboards-plugin
< 2.19.6-r16
- chainguard•opensearch-dashboards-2-security-dashboards-plugin
< 2.19.6-r16
- chainguard•opensearch-dashboards-3
< 3.8.0-r1
- chainguard•opensearch-dashboards-3-alerting-dashboards-plugin
< 3.8.0-r1
- chainguard•opensearch-dashboards-3-anomaly-detection-dashboards-plugin
< 3.8.0-r1
- chainguard•opensearch-dashboards-3-dashboards-maps
< 3.8.0-r1
- chainguard•opensearch-dashboards-3-dashboards-notifications
< 3.8.0-r1
- chainguard•opensearch-dashboards-3-dashboards-observability
< 3.8.0-r1
Showing first 50 affected entries in server-rendered view.
References (14)
- https://github.com/fastify/fast-uri/security/advisories/GHSA-fph4-wmhf-6fwf
- https://cna.openjsf.org/security-advisories.html
- https://security-tracker.debian.org/tracker/CVE-2026-75899
- https://ubuntu.com/security/CVE-2026-75899
- https://www.cve.org/CVERecord?id=CVE-2026-75899
- https://nvd.nist.gov/vuln/detail/CVE-2026-75899
- https://github.com/fastify/fast-uri/commit/2642290672e7211c990aaed3749c2ce667d0af4f
- https://github.com/fastify/fast-uri/commit/8c15dbe94ec50bb8e595791ebb42c35cef0fd304
- https://github.com/fastify/fast-uri/commit/ae92a4c5d8c4b6c9e447f048d5fcbde7eebd5514
- https://github.com/fastify/fast-uri
- https://github.com/fastify/fast-uri/releases/tag/v2.4.5
- https://github.com/fastify/fast-uri/releases/tag/v3.1.6
- https://github.com/fastify/fast-uri/releases/tag/v4.1.3
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75899.json