# CVE-2026-123575: Hickory DNS before 0.26.2 DoH Memory Exhaustion via Incomplete Request Bodies


- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 8 Nov 2026
- **Updated:** 8 Nov 2026
- **Also known as:** DEBIAN-CVE-2026-123575, GHSA-g5xf-qv55-wv37, GHSA-p3hw-2hh6-3p6w, UBUNTU-CVE-2026-123575

## What is CVE-2026-123575?

CVE-2026-123575 is a high-severity vulnerability in hickory-dns, published on 8 Nov 2026. 

### Official description

Hickory DNS before 0.26.2 contains a resource exhaustion vulnerability in its DNS-over-HTTPS HTTP/2 server that lacks sufficient timeouts or limits for incomplete request bodies. Remote attackers can open DoH connections, send incomplete request bodies, and hold connections open to exhaust server memory.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-123575?


## How do I fix CVE-2026-123575?

Upgrade to a fixed version.

## Is CVE-2026-123575 being exploited?

There is no known exploitation of CVE-2026-123575 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123575 and fix it if it is affected.

What it is: CVE-2026-123575 is a high-severity vulnerability in hickory-dns, published on 8 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123575 in the wild and no public exploit code.

Affected product: hickory-dns. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-123575/ (Markdown: https://insights.sbomify.com/CVE-2026-123575/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123575
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123575
- OSV: https://osv.dev/vulnerability/CVE-2026-123575

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123575/
Summaries are generated and may contain mistakes; the official description above is the record.