# CVE-2026-8368: libwww-perl LWP::UserAgent credential leak on cross-origin redirects

Source: https://junglewise.ai/threats/cve-2026-8368-libwww-perl-lwp-useragent-credential-leak-on-cross-origin  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-12. Updated: 2026-05-19  
License: CC BY 4.0 with a link back

CVE-2026-8368 · Severity: medium · CVSS 6.5 · Published 2026-05-12

A vulnerability in a popular Perl web library could allow attackers to steal sensitive login credentials. When the library follows a link that redirects to a different website, it fails to remove security tokens and passwords from the request. An attacker who controls a website can use this to trick the library into sending them a user's private authentication data.

Vendors: [Libwww-Perl](https://junglewise.ai/threats/vendors/libwww-perl).

## Quick answers

**Is CVE-2026-8368 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-8368 being exploited in the wild.

**How severe is CVE-2026-8368?** Medium severity, with a CVSS score of 6.5, published 12 May 2026.

**Which products and versions are affected?** Libwww-Perl < 6.83.

**Is there a fix for CVE-2026-8368?** A patch was published on 2026-05-12: libwww-perl 6.83 released. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-8368 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-8368?** Check whether you run Libwww-Perl at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

LWP::UserAgent in libwww-perl versions prior to 6.83 contains a credential leak vulnerability (CWE-522). When handling HTTP 3xx redirects, the library's redirect handler only strips 'Host' and 'Cookie' headers before issuing the follow-up request. If a request is redirected to a different origin (different scheme, host, or port), caller-supplied 'Authorization' and 'Proxy-Authorization' headers are forwarded unchanged. An attacker can exploit this by inducing a redirect to a malicious server to capture these credentials. The issue is fixed in version 6.83, which now strips these headers on cross-origin redirects unless the 'allow_credentialed_redirects' option is explicitly enabled.

## Affected products

- libwww-perl project libwww-perl < 6.83

## Timeline

- 2026-05-11: disclosed: Issue reported to maintainers.
- 2026-05-12: patched: libwww-perl 6.83 released.
- 2026-05-12: advisory: Public disclosure of CVE-2026-8368.

## References

- [https://github.com/libwww-perl/libwww-perl/commit/9c4aeb6f2dd32f2b7eaf2d7827cade31ea6cb2c6.patch](https://github.com/libwww-perl/libwww-perl/commit/9c4aeb6f2dd32f2b7eaf2d7827cade31ea6cb2c6.patch)
- [https://github.com/libwww-perl/libwww-perl/pull/284](https://github.com/libwww-perl/libwww-perl/pull/284)
- [https://github.com/libwww-perl/libwww-perl/pull/512](https://github.com/libwww-perl/libwww-perl/pull/512)
- [https://metacpan.org/release/OALDERS/libwww-perl-6.83/changes](https://metacpan.org/release/OALDERS/libwww-perl-6.83/changes)
- [http://www.openwall.com/lists/oss-security/2026/05/12/7](http://www.openwall.com/lists/oss-security/2026/05/12/7)