# CVE-2026-55484: alos-http has unauthenticated remote DoS: malformed path starting with "?" triggers out-of-bounds panic in sanitizeRequestPath, crashing entire server

> Unauthenticated attackers can crash the ALOS HTTP server by sending a malformed request path starting with a question mark, causing an out-of-bounds panic.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** GHSA-hr6j-w4mw-g9mj, GO-2026-6321

## What is CVE-2026-55484?

CVE-2026-55484 is a high-severity denial of service vulnerability in guno1928 alos-http, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions), CWE-248 (Uncaught Exception)

## Which versions are affected by CVE-2026-55484?

3 open source packages ship an affected version, including github.com/guno1928/alos-http.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/guno1928/alos-http` | Go | All versions | 0.0.0-20260617230736-314b6783e196 |
| `github.com/guno1928/alos-http` | Go | All versions | 0.0.0-20260617230736-314b6783e196 |
| `github.com/guno1928/alos-http` | Go | All versions | 0.0.0-20260617230736-314b6783e196 |

## How do I fix CVE-2026-55484?

Upgrade github.com/guno1928/alos-http to 0.0.0-20260617230736-314b6783e196 or later.

## Is CVE-2026-55484 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55484 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55484 and fix it if it is affected.

What it is: CVE-2026-55484 is a high-severity denial of service vulnerability in guno1928 alos-http, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55484 exists.

Affected packages and fixed versions:
- github.com/guno1928/alos-http (Go): affected all versions; fixed in 0.0.0-20260617230736-314b6783e196
- github.com/guno1928/alos-http (Go): affected all versions; fixed in 0.0.0-20260617230736-314b6783e196
- github.com/guno1928/alos-http (Go): affected all versions; fixed in 0.0.0-20260617230736-314b6783e196

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55484/ (Markdown: https://insights.sbomify.com/CVE-2026-55484/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55484
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55484
- OSV: https://osv.dev/vulnerability/CVE-2026-55484

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55484/
Summaries are generated and may contain mistakes; the official description above is the record.