Answer in brief
CVE-2025-34468 records a High severity (CVSS 8.2) vulnerability in libcoap Stack-Based Buffer Overflow in Address Resolution DoS or Potential RCE. The current sources do not mark it as known exploited. The current feed maps libcoap/libcoap (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps libcoap/libcoap (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:libcoap:libcoap:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| libcoap/libcoapgeneric | >=0 <=4.3.5 | Not reported |
Published upstream
Dec 31, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 29, 2026
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).
Quoted source text, attributed separately from HOL analysis.