libcoap 4.3.1 contains a buffer over-read via the function coap_parse_oscore_conf_mem at coap_oscore.c.

published 2023-06-19 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-39855

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits: 0; none known

Patch / fix

links 1

github.com/obgm/libcoap#1118 pull request

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-35862 updated 2026-03-27 cvss 6.5

libcoap: buffer over-read via coap_parse_oscore_conf_mem() at coap_oscore.c

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 22 mo ago (2024-12-11)

Exploit prediction

0.76% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/obgm/libcoap/issues/1117 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Classification

Weakness

CWE-125 Out-of-bounds Read

References

github.com /obgm/libcoap/pull/1118
patch
github.com /obgm/libcoap/issues/1117
exploit, issue-tracking, third-party-advisory
github.com /obgm/libcoap/tags
product

Sources

CVE List CVE-2023-35862
NVD CVE-2023-35862

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary