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TI-2026-42323 Aliases CVE-2026-59157GHSA-v25g-mvwr-f5fp

webhookd: Unrestricted HTTP Header to Shell Variable Injection

Priority LOW 36CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-290.

Summary

webhookd is a minimalist webhook server that triggers shell scripts and external processes through HTTP requests. Prior to 1.22.0, webhookd deployments without htpasswd authentication forwarded all incoming HTTP headers through HTTPParamsToShellVars in pkg/api/index.go into the hook script environment without an allowlist. When an upstream reverse proxy did not strip a client-supplied X-WebAuthn-User header and a hook script trusted that variable for identity or privilege, a remote unauthenticated attacker could spoof another user, bypass script security controls, and access or modify resources available to the impersonated identity. This issue is fixed in version 1.22.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00596 48th percentileScored 2026-11-07
Fix Fixed webhookd (ncarlier): 1.22github.com/ncarlier/webhookd (Go): 1.22.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ncarlierwebhookdbefore 1.221.22Patch availableCNA
—github.com/ncarlier/webhookd (Go)before 1.22.01.22.0Patch availableGHSA-v25g-mvwr-f5fp
  • webhookd Vendorncarlier Affected before 1.22 Fixed in 1.22 Patch available CNA
  • github.com/ncarlier/webhookd (Go) Vendor— Affected before 1.22.0 Fixed in 1.22.0 Patch available GHSA-v25g-mvwr-f5fp

Remediation

  • Fix · CNA webhookd (ncarlier) Fixed in 1.22
  • Fix · GHSA-v25g-mvwr-f5fp github.com/ncarlier/webhookd (Go) Fixed in 1.22.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-59157
  2. 2026-10-03 Alias added: GHSA-v25g-mvwr-f5fp

References

Other 5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences