CVE-2026-16729

Description

undici's setCookie function does not fully sanitize cookie attributes. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a domain value is not checked for semicolons and entries in the unparsed array are not sanitized, so attacker-influenced input can inject additional cookie attributes. For example, a domain value containing a semicolon can append attributes such as SameSite, and an unparsed entry can inject attributes such as HttpOnly, without the caller setting them. Applications that pass user-controlled input to these fields, such as multi-tenant or reverse-proxy servers that scope session cookies to a tenant-supplied domain, can have SameSite CSRF protections bypassed, or the Secure, HttpOnly, and SameSite attributes forced, stripped, or overridden. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.

CVSS Metrics

• v3.1•MEDIUM•Score: 4.8CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
• v3.1•MEDIUM•Score: 6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS Trends

Current EPSS score: 0.19%• Percentile: 9%

Techniques & Countermeasures

• CWE-74•Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

  The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

Affected Systems

• chainguard•actions-runner

  < 2.336.0-r5

• chainguard•code-server

  < 4.130.0-r5

• chainguard•commercial-gitlab-rails-ee-19.1

  all

• chainguard•commercial-gitlab-rails-ee-19.2

  all

• chainguard•commercial-gitlab-rails-ee-19.3

  all

• chainguard•commercial-gitlab-rails-ee-fips-19.1

  all

• chainguard•commercial-gitlab-rails-ee-fips-19.2

  all

• chainguard•commercial-gitlab-rails-ee-fips-19.3

  all

• chainguard•kibana-8.19

  < 8.19.20-r2

• chainguard•kibana-8.19-bitnami

  < 8.19.20-r2

• chainguard•kibana-8.19-iamguarded

  < 8.19.20-r2

• chainguard•kibana-9.1

  all

• chainguard•kibana-9.1-iamguarded

  all

• chainguard•kibana-9.2

  < 9.2.8-r19

• chainguard•kibana-9.2-iamguarded

  < 9.2.8-r19

• chainguard•kibana-9.3

  all

• chainguard•kibana-9.3-iamguarded

  all

• chainguard•langfuse-3

  < 3.225.0-r3

• chainguard•langfuse-3-compat

  < 3.225.7-r6

• chainguard•langfuse-3-worker

  < 3.225.0-r3

• chainguard•langfuse-4

  < 4.3.1-r3

• chainguard•langfuse-4-worker

  < 4.3.1-r3

• chainguard•langfuse-fips-3

  < 3.224.3-r9

• chainguard•langfuse-fips-3-worker

  < 3.224.3-r9

• chainguard•langfuse-fips-4

  < 4.4.0-r0

• chainguard•langfuse-fips-4-worker

  < 4.4.0-r0

• chainguard•npm-12

  < 12.0.2-r2

• chainguard•pelias-api

  < 7.8.0-r7

• chainguard•prism

  < 5.16.0-r2

• chainguard•pulumi-language-nodejs

  < 3.256.0-r1

• chainguard•renovate

  < 44.23.3-r1 | < 44.11.3-r0 | < 44.11.4-r0

• chainguard•saf

  < 1.7.0-r0

• chainguard•vitess-24

  < 24.0.2-r10

• chainguard•vitess-24-compat

  < 24.0.3-r7

• wolfi•code-server

  < 4.130.0-r5

• wolfi•langfuse-3

  < 3.225.0-r3

• wolfi•langfuse-3-compat

  < 3.225.7-r6

• wolfi•langfuse-3-worker

  < 3.225.0-r3

• wolfi•npm-12

  < 12.0.2-r2

• wolfi•prism

  < 5.16.0-r2

• wolfi•pulumi-language-nodejs

  < 3.256.0-r1

• wolfi•renovate

  < 44.23.3-r1 | < 44.11.3-r0 | < 44.11.4-r0

• wolfi•saf

  < 1.7.0-r0

• wolfi•vitess-24

  < 24.0.2-r10

• wolfi•vitess-24-compat

  < 24.0.3-r7

• debian•node-undici

  all | all | < 8.9.0+dfsg+~cs3.2.0-1

• ubuntu•node-undici

  all | all

• nodejs•undici

  < 6.28.0 | ≥ 7.0.0, < 7.29.0 | ≥ 8.0.0, < 8.9.0

• Npm•undici

  < 6.28.0 | ≥ 7.0.0, < 7.29.0 | ≥ 8.0.0, < 8.9.0

• undici•undici

  < 6.28.0 | ≥ 7.0.0, < 7.29.0 | ≥ 8.0.0, < 8.9.0

References (14)

• https://github.com/nodejs/undici/security/advisories/GHSA-v3r7-h72x-cjcm
• https://cna.openjsf.org/security-advisories.html
• https://ubuntu.com/security/CVE-2026-16729
• https://www.cve.org/CVERecord?id=CVE-2026-16729
• https://security-tracker.debian.org/tracker/CVE-2026-16729
• https://nvd.nist.gov/vuln/detail/CVE-2026-16729
• https://github.com/nodejs/undici/commit/10d93fc332f2c8c161982dec3833201de29891b5
• https://github.com/nodejs/undici/commit/3bf91ddb493e853957f3a58e155326a668ab8aef
• https://github.com/nodejs/undici/commit/af7484043ee075a6f216da0ad77e1dac55199235
• https://github.com/nodejs/undici
• https://github.com/nodejs/undici/releases/tag/v6.28.0
• https://github.com/nodejs/undici/releases/tag/v7.29.0
• https://github.com/nodejs/undici/releases/tag/v8.9.0
• https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16729.json