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TI-2025-24520 Aliases CVE-2025-34468GHSA-rj9f-6c28-qf6x

libcoap Stack-Based Buffer Overflow in Address Resolution DoS or Potential RCE

Priority LOW 37CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

libcoap versions up to and including 4.3.5, prior to commit 30db3ea, contain a stack-based buffer overflow in address resolution when attacker-controlled hostname data is copied into a fixed 256-byte stack buffer without proper bounds checking. A remote attacker can trigger a crash and potentially achieve remote code execution depending on compiler options and runtime memory protections. Exploitation requires the proxy logic to be enabled (i.e., the proxy request handling code path in an application using libcoap).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00748 55th percentileScored 2026-11-07
Fix Fixed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
libcoaplibcoapup to 4.3.5—Patch availableCNA
  • libcoap Vendorlibcoap Affected up to 4.3.5 Fixed in — Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:libcoap:libcoap:*:*:*:*:*:*:*:*up to 4.3.5Vulnerablelibcoap
  • cpe:2.3:a:libcoap:libcoap:*:*:*:*:*:*:*:* Versions up to 4.3.5 Vulnerable ·libcoap

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-34468
  2. 2026-10-03 Alias added: GHSA-rj9f-6c28-qf6x

References

Patch 2

Other 1

  • TI-2024-00887 obgm libcoap Configuration File coap_oscore.c get_split_entry stack-based overflow CVSS 3.1HIGH 7.8
  • TI-2024-20447 An issue in `coap_pdu.c` in libcoap 4.3.4 allows attackers to cause undefined behavior… CVSS 3.1HIGH 7.5
  • TI-2023-17937 libcoap 4.3.1 contains a buffer over-read via the function coap_parse_oscore_conf_mem at coap_oscore.c. CVSS 3.1MEDIUM 6.5
  • TI-2026-23178 libcoap Out-of-Bounds Read in OSCORE CBOR Unwrap Handling CVSS 4.0HIGH 8.8
  • TI-2023-14242 Buffer Overflow vulnerability in coap_send function in libcoap library 4.3.1-103-g52cfd56… CVSS 3.1HIGH 7.5
  • TI-2025-40369 NULL pointer dereference in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote… CVSS 3.1HIGH 7.5
See all 15 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences