Out-of-bounds Read in Libcoap
CVE-2025-59391
A memory disclosure vulnerability exists in libcoap's OSCORE configuration parser in libcoap before release-4.3.5-patches. An out-of-bounds read may occur when parsing certain configuration values, allowing an attacker to infer or read memory beyond string boundaries in the .rodata section. This could potentially lead to information disclosure or denial of service.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.
EPSS exploit prediction
EPSS: 0.003 (16.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/obgm/libcoap/releases/tag/v4.3.5a (Release Notes)
- github.com/obgm/libcoap/pull/1730 (Patch, Issue Tracking)
Frequently asked questions
- What is CVE-2025-59391?
- CVE-2025-59391 is a medium-severity vulnerability in Libcoap, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2025-12-08.
- How severe is CVE-2025-59391?
- Medium severity. CVSS v3 base score is 6.5 out of 10.