CVE-2026-8368: LWP::UserAgent versions before 6.83 for Perl leak Authorization and Proxy-Authorization headers on cross-origin redirects
Stig Palmquist 12 May 2026 14:07 UTC
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CVE-2026-8368 CPAN Security Group
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CVE ID: CVE-2026-8368
Distribution: libwww-perl
Versions: before 6.83
MetaCPAN: https://metacpan.org/dist/libwww-perl
VCS Repo: https://github.com/libwww-perl/libwww-perl
LWP::UserAgent versions before 6.83 for Perl leak Authorization and
Proxy-Authorization headers on cross-origin redirects
Description
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LWP::UserAgent versions before 6.83 for Perl leak Authorization and
Proxy-Authorization headers on cross-origin redirects.
On a 3xx response, the redirect handler strips only Host and Cookie
before issuing the follow-up request. Caller-supplied Authorization and
Proxy-Authorization headers are sent unchanged to the redirect target,
including across scheme, host, or port changes.
A redirect to an attacker controlled host therefore discloses the
caller's credentials to that host.
Problem types
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- CWE-522 Insufficiently Protected Credentials
Solutions
---------
Upgrade to libwww-perl 6.83 or later.
References
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https://github.com/libwww-perl/libwww-perl/commit/9c4aeb6f2dd32f2b7eaf2d7827cade31ea6cb2c6.patch
https://metacpan.org/release/OALDERS/libwww-perl-6.83/changes
https://github.com/libwww-perl/libwww-perl/pull/512
https://github.com/libwww-perl/libwww-perl/pull/284
Timeline
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- 2026-05-11: Issue reported.
- 2026-05-12: libwww-perl 6.83 released with fix.
Credits
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Kai Aizen, reporter