CyberSecBulletin
CVE-2026-44359NVD status: Deferred

firmware: Improper Control of Generation of Code

Published Updated By the CyberSecBulletin desk

CVE-2026-44359 is a critical-severity improper control of generation of code vulnerability in firmware from Meshtastic, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected firmware versions: < 2.7.21.1370b23. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.8% chance of exploitation within 30 days, higher than 79% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of firmware you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Meshtasticfirmware< 2.7.21.1370b23Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (github.com).

Official description

Meshtastic is an open source mesh networking solution. Prior to version 2.7.21.1370b23, the Meshtastic GitHub repository's main_matrix.yml workflow is triggered by pull_request_target and multiple jobs check out the attacker's fork code and execute it with access to repository secrets and elevated GITHUB_TOKEN permissions. No approval gate exists. Pull requests from external users with author_association: "NONE" triggered the CI workflow automatically. The workflow directly executes attacker-controlled files from the fork checkout. This issue could have resulted in supply chain compromise, self-hosted runner compromise, and/or repository takeover for the repo. This issue is separate from GHSA-6mwm-v2vv-pp96, which addressed a command injection via github.head_ref in the setup job of the same workflow. That fix correctly moved to environment variables. However, the more critical fork checkout vulnerability across the check, build, and build-debian-src jobs was not addressed. Version 2.7.21.1370b23 contains a patch for thie issue.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How developers prevent this class of flaw

  • Refactor your program so that you do not have to dynamically generate code.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

More Improper Control of Generation of Code vulnerabilities (CWE-94)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in firmware

All firmware vulnerabilities

Recent Improper Control of Generation of Code vulnerabilities

Spotted an error? Tell us.