# CVE-2026-23749: Golioth Firmware SDK < 0.22.0 Blockwise Transfer Path Out-of-Bounds Read

> An out-of-bounds read in the Golioth Firmware SDK can cause a crash when processing blockwise transfer paths, leading to denial of service.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Feb 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-2qjx-h626-j6v4

## What is CVE-2026-23749?

CVE-2026-23749 is a low-severity memory corruption vulnerability in Golioth Firmware SDK, published on 26 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Golioth Firmware SDK version 0.19.1 prior to 0.22.0, fixed in commit 0e788217, contain an out-of-bounds read due to improper null termination of a blockwise transfer path. blockwise_transfer_init() accepts a path whose length equals CONFIG_GOLIOTH_COAP_MAX_PATH_LEN and copies it using strncpy() without guaranteeing a trailing NUL byte, leaving ctx->path unterminated. A later strlen() on this buffer (in golioth_coap_client_get_internal()) can read past the end of the allocation, resulting in a crash/denial of service. The input is application-controlled (not network by default).

Weakness: CWE-170 (Improper Null Termination)

## Which versions are affected by CVE-2026-23749?


## How do I fix CVE-2026-23749?

No fix has been published for CVE-2026-23749 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-23749 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-23749 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23749 and fix it if it is affected.

What it is: CVE-2026-23749 is a low-severity memory corruption vulnerability in Golioth Firmware SDK, published on 26 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-23749 exists.

Affected product: Golioth Firmware SDK. 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-2026-23749/ (Markdown: https://insights.sbomify.com/CVE-2026-23749/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23749
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23749
- OSV: https://osv.dev/vulnerability/CVE-2026-23749

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23749/
Summaries are generated and may contain mistakes; the official description above is the record.