Medium

Next.js: null origin can bypass Server Actions CSRF checks

  • Disclosed: 17.03.2026
  • Updated: 11.10.2026 10:22

Summary

origin: null was treated as a "missing" origin during Server Action CSRF validation. As a result, requests from opaque contexts (such as sandboxed iframes) could bypass origin verification instead of being validated as cross-origin requests.

Impact

An attacker could induce a victim browser to submit Server Actions from a sandboxed context, potentially executing state-changing actions with victim credentials (CSRF).

Patches

Fixed by treating 'null' as an explicit origin value and enforcing host/origin checks unless 'null' is explicitly allowlisted in experimental.serverActions.allowedOrigins.

Workarounds

If upgrade is not immediately possible:

  • Add CSRF tokens for sensitive Server Actions.
  • Prefer SameSite=Strict on sensitive auth cookies.
  • Do not allow 'null' in serverActions.allowedOrigins unless intentionally required and additionally protected.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package next >= 16.0.1, < 16.1.7 16.1.7

References

CVSS score -
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Weakness (CWE)
CWE-352
Platform
npm
Package
next
Disclosed
17.03.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-mq59-m269-xvcx - CC BY 4.0

Vulnerability history: next

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (73) in the archive
Total entries
73
First → latest
12.2017 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 5
  • High 27
  • Medium 32
  • Low 9

Disclosures per year

  1. 2017: 1
  2. 2018: 2
  3. 2019: 0
  4. 2020: 3
  5. 2021: 3
  6. 2022: 3
  7. 2023: 1
  8. 2024: 6
  9. 2025: 14
  10. 2026: 40
Severity:
  1. High · 6.5 CVE-2026-94483 >= 16.0.0, < 16.3.8 16.3.8
  2. Critical ghsa-vcvr-r3jv-pc5j >= 16.2.0, < 16.3.6 16.3.6
  3. Critical ghsa-2xp9-vwfh-vxw4 >= 10.0.0, < 15.5.24, >= 16.0.0, < 16.3.3 15.5.24, 16.3.3
  4. Critical · 9.0 CVE-2026-75604 >= 13.4.0, < 15.5.24, >= 16.0.0, < 16.3.3 15.5.24, 16.3.3
  5. High CVE-2026-64649 >= 14.1.1, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  6. High CVE-2026-64645 >= 12.0.0, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  7. High CVE-2026-64641 >= 13.0.0, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  8. High · 7.5 CVE-2026-45109 >= 15.2.0, < 15.5.18, >= 16.0.0, < 16.2.6 15.5.18, 16.2.6
  9. High · 7.5 CVE-2026-44579 >= 15.0.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  10. High · 8.6 CVE-2026-44578 >= 13.4.13, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  11. High · 7.5 CVE-2026-44575 >= 15.2.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  12. High · 8.1 CVE-2026-44574 >= 15.4.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  13. High · 7.5 CVE-2026-44573 >= 12.2.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  14. High · 7.5 ghsa-8h8q-6873-q5fj >= 13.0.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  15. High · 7.5 ghsa-q4gf-8mx6-v5v3 >= 13.0.0, < 15.5.15, >= 16.0.0-beta.0, < 16.2.3 15.5.15, 16.2.3
  16. Next.js: null origin can bypass Server Actions CSRF checks this entry
    Medium CVE-2026-27978 >= 16.0.1, < 16.1.7 16.1.7
  17. High · 7.5 ghsa-h25m-26qc-wcjf >= 13.0.0, < 15.0.8, >= 15.1.1-canary.0, < 15.1.12, >= 15.2.0-canary.0, < 15.2.9, >= 15.3.0-canary.0, < 15.3.9, >= 15.4.0-canary.0, < 15.4.11, >= 15.5.1-canary.0, < 15.5.10, >= 15.6.0-canary.0, < 15.6.0-canary.61, >= 16.0.0-beta.0, < 16.0.11, >= 16.1.0-canary.0, < 16.1.5 15.0.8, 15.1.12, 15.2.9, 15.3.9, 15.4.11, 15.5.10, 15.6.0-canary.61, 16.0.11, 16.1.5
  18. High · 7.5 ghsa-5j59-xgg2-r9c4 >= 13.3.1-canary.0, < 14.2.35, >= 15.0.6, < 15.0.7, >= 15.1.10, < 15.1.11, >= 15.2.7, < 15.2.8, >= 15.3.7, < 15.3.8, >= 15.4.9, < 15.4.10, >= 15.5.8, < 15.5.9, >= 15.6.0-canary.59, < 15.6.0-canary.60, >= 16.0.9, < 16.0.10, >= 16.1.0-canary.17, < 16.1.0-canary.19 14.2.35, 15.0.7, 15.1.11, 15.2.8, 15.3.8, 15.4.10, 15.5.9, 15.6.0-canary.60, 16.0.10, 16.1.0-canary.19
  19. High · 7.5 ghsa-mwv6-3258-q52c >= 13.3.0, < 14.2.34, >= 15.0.0-canary.0, < 15.0.6, >= 15.1.1-canary.0, < 15.1.10, >= 15.2.0-canary.0, < 15.2.7, >= 15.3.0-canary.0, < 15.3.7, >= 15.4.0-canary.0, < 15.4.9, >= 15.5.1-canary.0, < 15.5.8, >= 15.6.0-canary.0, < 15.6.0-canary.59, >= 16.0.0-beta.0, < 16.0.9, >= 16.1.0-canary.0, < 16.1.0-canary.17 14.2.34, 15.0.6, 15.1.10, 15.2.7, 15.3.7, 15.4.9, 15.5.8, 15.6.0-canary.59, 16.0.9, 16.1.0-canary.17
Show more (13) Showing 20 of 33

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