# CVE-2026-58465: Eclipse Wakaama CoAP Block1 Handler Unbounded Memory Allocation DoS

> Unauthenticated remote attackers can cause denial of service in Eclipse Wakaama by exhausting server memory via unbounded Block1 PUT requests.

- **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
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-95xc-mgc7-g4jq

## What is CVE-2026-58465?

CVE-2026-58465 is a high-severity denial of service vulnerability in eclipse-wakaama wakaama, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Eclipse Wakaama before snapshot/2026-05-26 contains an unbounded memory allocation vulnerability in the CoAP Block1 handler within coap/block.c that allows unauthenticated remote attackers to exhaust server memory by sending a sequence of Block1 PUT requests with incrementing block numbers. Attackers can target the registration endpoint over UDP without authentication, causing the server to repeatedly reallocate a growing accumulation buffer by appending each block payload without enforcing any maximum total size limit, resulting in denial of service through memory exhaustion.

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

## Which versions are affected by CVE-2026-58465?


## How do I fix CVE-2026-58465?

No fix has been published for CVE-2026-58465 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-58465 being exploited?

There is no known exploitation of CVE-2026-58465 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58465 and fix it if it is affected.

What it is: CVE-2026-58465 is a high-severity denial of service vulnerability in eclipse-wakaama wakaama, published on 2 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-58465 in the wild and no public exploit code.

Affected product: eclipse-wakaama wakaama. 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-2026-58465/ (Markdown: https://insights.sbomify.com/CVE-2026-58465/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58465
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58465
- OSV: https://osv.dev/vulnerability/CVE-2026-58465

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58465/
Summaries are generated and may contain mistakes; the official description above is the record.