alos-http has unauthenticated remote DoS: malformed path starting with "?" triggers out-of-bounds panic in sanitizeRequestPath, crashing entire server

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-55484: 0.49% estimated exploitation activity in the next 30 days; percentile 42.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A single unauthenticated HTTP request to a path starting with ? (e.g. GET ? HTTP/1.1) crashes the entire server process. The request line parser passes the path to sanitizeRequestPath which indexes the first byte of the path after stripping the query string. It does so without checking that it is non-empty, leading to an out-of-bounds panic. The panic occurs before any handler or middleware runs so core.Recovery() does not recover it. The entire process panics and every connection is dropped. It is reachable over HTTP/1.1, HTTP/2 and HTTP/3 if ListenAndServeQUIC is enabled Details root cause: core/utils.go::sanitizeRequestPath when the path starts with "?" len(path) is not 0 so the early return does not fire after splitPathQuery p is empty "" p is then indexed p[0] without a length check Relevant calling sites: h1plain.go:ParseH1RequestHead (HTTP/1.1) h1.go::ParseH1Request (dead code) hpack.go::decodeSimpleGetPathHTTPSRequest (HTTP/2) hpack.go::observeHeader (HTTP/2)…

Published by the source

28 Aug 2026, 19:19 UTC

Last modified by the source

2 Sep 2026, 19:45 UTC

Source last checked

26 Oct 2026, 15:28 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hr6j-w4mw-g9mj

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6321

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hr6j-w4mw-g9mj

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# Patch Next advisory brief: CVE-2026-55484

Advisory: alos-http has unauthenticated remote DoS: malformed path starting with "?" triggers out-of-bounds panic in sanitizeRequestPath, crashing entire server
IDs: CVE-2026-55484, GHSA-hr6j-w4mw-g9mj
Record: https://patchnext.com/advisories/cve-2026-55484 (revision 3, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/guno1928/alos-http 0.0.0-20260617230736-314b6783e196. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/guno1928/alos-http: affected < 0.0.0-20260617230736-314b6783e196; fixed in 0.0.0-20260617230736-314b6783e196

## Suggested inspection (read-only)
- Go github.com/guno1928/alos-http: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/guno1928/alos-http.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-hr6j-w4mw-g9mj (OSV record GHSA-hr6j-w4mw-g9mj lists affected ranges: Go github.com/guno1928/alos-http >=0 <0.0.0-20260617230736-314b6783e196 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6321 (OSV record GO-2026-6321 lists affected ranges: Go github.com/guno1928/alos-http >=0 <0.0.0-20260617230736-314b6783e196 (fixed))
- Verified: https://github.com/advisories/GHSA-hr6j-w4mw-g9mj (GitHub-reviewed advisory GHSA-hr6j-w4mw-g9mj lists affected ranges: Go github.com/guno1928/alos-http >=0 <0.0.0-20260617230736-314b6783e196)

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