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TI-2026-32300 Aliases CVE-2026-44332GHSA-g5vh-55hw-rxm8

Fiber: Username Enumeration via Timing Oracle in BasicAuth Default Authorizer

Priority LOW 31CWE-203Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-203.

Summary

Fiber is an Express inspired web framework written in Go. Prior to 3.3.0, the default Authorizer function in the BasicAuth middleware in middleware/basicauth/config.go uses short-circuit evaluation that skips password hash comparison for non-existent usernames, enabling reliable remote username enumeration through response timing differences. This issue is fixed in version 3.3.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00517 44th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed fiber (gofiber): 3.3.0github.com/gofiber/fiber/v3 (Go): 3.3.0

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
gofiberfiberbefore 3.3.03.3.0Patch availableCNA
—github.com/gofiber/fiber/v3 (Go)before 3.3.03.3.0Patch availableGHSA-g5vh-55hw-rxm8
  • fiber Vendorgofiber Affected before 3.3.0 Fixed in 3.3.0 Patch available CNA
  • github.com/gofiber/fiber/v3 (Go) Vendor— Affected before 3.3.0 Fixed in 3.3.0 Patch available GHSA-g5vh-55hw-rxm8

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:gofiber:fiber:*:*:*:*:*:go:*:*before 3.3.0Vulnerablegofiber
  • cpe:2.3:a:gofiber:fiber:*:*:*:*:*:go:*:* Versions before 3.3.0 Vulnerable ·gofiber

Remediation

  • Fix · CNA fiber (gofiber) Fixed in 3.3.0
  • Fix · GHSA-g5vh-55hw-rxm8 github.com/gofiber/fiber/v3 (Go) Fixed in 3.3.0 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-44332
  2. 2026-10-03 Alias added: GHSA-g5vh-55hw-rxm8

References

Exploit 1

Patch 2

Other 2

  • TI-2025-34555 Fiber Susceptible to Crash via `BodyParser` Due to Unvalidated Large Slice Index in Decoder CVSS 4.0HIGH 8.7
  • TI-2024-16578 Fiber has Insecure CORS Configuration, Allowing Wildcard Origin with Credentials CVSS 3.1CRITICAL 9.8
  • TI-2025-30446 Fiber panics when fiber.Ctx.BodyParser parses invalid range index CVSS 4.0HIGH 7.7
  • TI-2026-23477 github.com/gofiber/fiber/v3 cache middleware can mix responses across query parameters CVSS 3.1MEDIUM 6.5
  • TI-2026-20922 Fiber has a Denial of Service Vulnerability via Route Parameter Overflow CVSS 4.0MEDIUM 5.5
  • TI-2026-30834 Fiber: XSS in AutoFormat Content Negotiation CVSS 4.0MEDIUM 5.3
See all 16 →

Sources

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