CVE-2025-15104

NameCVE-2025-15104
DescriptionNu Html Checker (validator.nu) contains a restriction bypass that allows remote attackers to make the server perform arbitrary HTTP/HTTPS requests to internal resources, including localhost services. While the validator implements hostname-based protections to block direct access to localhost and 127.0.0.1, these controls can be bypassed using DNS rebinding techniques or domains that resolve to loopback addresses.This issue affects The Nu Html Checker (vnu): latest (commit 23f090a11bab8d0d4e698f1ffc197a4fe226a9cd).
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1136011

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
vnu (PTS)sid23.4.11+dfsg-3vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
vnusource(unstable)(unfixed)1136011

Notes

https://github.com/validator/validator/issues/2033
https://github.com/validator/validator/commit/b95c4190258db2769cff67cc09d323432bd7a99e (26.4.16)

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