What is CVE-2025-62689?

CVE-2025-62689 is a high-severity vulnerability in GNU Libmicrohttpd, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2025-11-10.

How severe is CVE-2025-62689?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in GNU Libmicrohttpd

CVE-2025-62689

NULL pointer dereference vulnerability exists in GNU libmicrohttpd v1.0.2 and earlier. The vulnerability was fixed in commit ff13abc on the master branch of the libmicrohttpd Git repository, after the v1.0.2 tag. A specially crafted packet sent by an attacker could cause a denial-of-service (DoS) condition.

Vulnerability class: Buffer Overflow

Published 2025-11-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (34.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

GNU Libmicrohttpd
GNU Project Libbmicrohttpd — versions 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, after the v1.0.2 tag.)

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

www.gnu.org/software/libmicrohttpd/ (Product)
git.gnunet.org/libmicrohttpd.git/commit/ (Patch)
jvn.jp/en/jp/JVN76719218/ (Third Party Advisory)

Frequently asked questions

What is CVE-2025-62689?: CVE-2025-62689 is a high-severity vulnerability in GNU Libmicrohttpd, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2025-11-10.
How severe is CVE-2025-62689?: High severity. CVSS v3 base score is 7.5 out of 10.