CVE-2026-29013
Libcoap out-of-bounds read
- Published17 Apr 2026
Description
libcoap contains out-of-bounds read vulnerabilities in OSCORE Appendix B.2 CBOR unwrap handling where get_byte_inc() in src/oscore/oscore_cbor.c relies solely on assert() for bounds checking, which is removed in release builds compiled with NDEBUG. Attackers can send crafted CoAP requests with malformed OSCORE options or responses during OSCORE negotiation to trigger out-of-bounds reads during CBOR parsing and potentially cause out-of-bounds reads through integer wraparound in allocation size computation.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-29013 being actively exploited?
CVE-2026-29013 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.52%.
How severe is CVE-2026-29013?
CVE-2026-29013 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.52% probability of exploitation.
Which products are affected by CVE-2026-29013?
Affected products include Libcoap.
How do I fix CVE-2026-29013?
Upgrade affected software to a fixed version, for example Libcoap 4.3.5b or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-29013 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.