Quick answers
- Is CVE-2026-29013 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-29013 being exploited in the wild.
- How severe is CVE-2026-29013?
- Critical severity, with a CVSS score of 9.8, published 17 April 2026.
- Which products and versions are affected?
- obgm libcoap up to (excluding) 4.3.5b.
- Is there a fix for CVE-2026-29013?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-29013 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-29013?
- Check whether you run Libcoap. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
libcoap is vulnerable to an out-of-bounds read in its OSCORE implementation, specifically within the CBOR unwrap handling in 'src/oscore/oscore_cbor.c'. The 'get_byte_inc()' function relies on 'assert()' for bounds checking; however, these assertions are stripped in production builds compiled with NDEBUG. A remote, unauthenticated attacker can exploit this by sending crafted CoAP requests with malformed OSCORE options or responses during negotiation. This can trigger out-of-bounds reads during CBOR parsing or cause integer wraparound during allocation size computation, potentially leading to memory corruption or information disclosure. A patch is available in the project's repository.
Affected products
- obgm libcoap up to (excluding) 4.3.5b
Timeline
- 2026-04-17: disclosed
- 2026-04-17: advisory
- 2026-06-02: other: NIST initial analysis completed