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CVE-2026-29013

libcoap Out-of-Bounds Read in OSCORE CBOR Unwrap Handling

CVSS 8.8 HIGHEPSS 0.3%CWE-125
Vexday Risk Score
21Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 8.8EPSS 0.3%KEV nãoPoC Nuclei Metasploit Patch referenciado
Lifecycle
17 Apr 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N
Affected products
libcoap · libcoap