What is CVE-2025-57785?

CVE-2025-57785 is a medium-severity vulnerability in Hiawatha Web Server, classified under Double Free. CVSS score: 6.5/10. Published 2026-01-26.

How severe is CVE-2025-57785?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Double Free in Hiawatha Web Server

CVE-2025-57785

A Double Free in XSLT `show_index` has been identified in Hiawatha webserver version 11.7 which allows an unauthenticated attacker to corrupt data which may lead to arbitrary code execution.

Vulnerability class: Double Free

Published 2026-01-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.4th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.4% 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

Hiawatha Web Server — versions 11.47
Hiawatha.leisink Hiawatha Webserver — versions 11.7

Weakness classification (CWE)

CWE-415 — Double Free

References

gitlab.com/hsleisink/hiawatha/-/blame/master/src/xslt.c (Release Notes)

Frequently asked questions

What is CVE-2025-57785?: CVE-2025-57785 is a medium-severity vulnerability in Hiawatha Web Server, classified under Double Free. CVSS score: 6.5/10. Published 2026-01-26.
How severe is CVE-2025-57785?: Medium severity. CVSS v3 base score is 6.5 out of 10.