Vulnerability-Lookup

GHSA-4VRR-6F8V-98RF

Vulnerability from github – Published: 2026-04-18 00:31 – Updated: 2026-04-18 00:31

Details

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 heap buffer overflow writes through integer wraparound in allocation size computation.

Severity ?

8.8 (High)


                  
                    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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-29013"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-17T22:16:31Z",
    "severity": "HIGH"
  },
  "details": "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 heap buffer overflow writes through integer wraparound in allocation size computation.",
  "id": "GHSA-4vrr-6f8v-98rf",
  "modified": "2026-04-18T00:31:03Z",
  "published": "2026-04-18T00:31:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-29013"
    },
    {
      "type": "WEB",
      "url": "https://github.com/obgm/libcoap/commit/b7847c4dbb0dbee7c90b09a673d4cae256f03718"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/libcoap-out-of-bounds-read-in-oscore-cbor-unwrap-handling"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-29013 (GCVE-0-2026-29013)

Vulnerability from cvelistv5 – Published: 2026-04-17 21:11 – Updated: 2026-04-20 16:46

Title

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

Summary

Severity ?

8.8 (High)


                        
                          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

CWE

CWE-125 - Out-of-bounds Read

Assigner

VulnCheck

References

URL

Tags

https://github.com/obgm/libcoap/commit/b7847c4dbb…

patch

Impacted products

	Vendor	Product	Version
	libcoap	libcoap	Affected: 0 , < v4.3.5b (custom)

Date Public ?

2026-04-17 00:00

Credits

Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc.

Show details on NVD website

JSON

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        "metrics": [
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                "id": "CVE-2026-29013",
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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-4VRR-6F8V-98RF

CVE-2026-29013 (GCVE-0-2026-29013)

Tags

Sightings

Nomenclature