CVE-2025-62689Network attack vector

Server crash via experimental WebSocket frame overflow

Published Nov 10, 2025 · Updated Nov 10, 2025

Heap-based buffer overflow in GNU libmicrohttpd 1.0.2 and earlier allows remote attackers to crash servers with a crafted packet. The experimental libmicrohttpd_ws.so WebSocket frame decoder writes beyond a heap allocation while processing the packet; the public advisory does not identify the exact function or field. Only builds made with --enable-experimental that embed libmicrohttpd_ws.so are exposed, and successful exploitation interrupts the hosting process without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap-based buffer overflow in GNU libmicrohttpd 1.0.2 and earlier allows remote attackers to crash servers with a crafted packet. The experimental libmicrohttpd_ws.so WebSocket frame decoder writes beyond a heap allocation while processing the packet; the public advisory does not identify the exact function or field. Only builds made with --enable-experimental that embed libmicrohttpd_ws.so are exposed, and successful exploitation interrupts the hosting process without reported data disclosure or modification.

The record

CVE
CVE-2025-62689
Published
Nov 10, 2025
Updated
Nov 10, 2025
Vendor
The GnuPG Project
Product
GNU libmicrohttpd
Classifications
CWE-122, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=after the v1.0.2 tag.)
  2. Affected versionversion=v1.0.2 and earlier (The vulnerability remains in the source code up until commit ff13abc on the master branch of the libmicrohttpd Git repository

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The GnuPG Project · GNU libmicrohttpdversion=after the v1.0.2 tag.); version=v1.0.2 and earlier (The vulnerability remains in the source code up until commit ff13abc on the master branch of the libmicrohttpd Git repository

Published CVSS scores

7.5JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo