# CVE-2026-8368: LWP::UserAgent versions before 6.83 for Perl leak Authorization and Proxy-Authorization headers on cross-origin redirects

CVE-2026-8368 is fixed in 3 products on 1 platform, first by libwww-perl 6.61-1ubuntu0.1, released May 12, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-8368
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0027
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 12, 2026
- Weakness: Insufficiently Protected Credentials
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-8368

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libwww-perl Debian 14 | 6.83-1 | [DEBIAN-CVE-2026-8368](https://patchblox.com/security/data/fix/linux/debian-cve-2026-8368.md) | May 27, 2026 |
| Linux | libwww-perl Ubuntu 22.04.1 LTS (jammy) | 6.61-1ubuntu0.1 | [libwww-perl 6.61-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libwww-perl-6.61-1ubuntu0.1.md) | May 12, 2026 |
| Linux | libwww-perl Ubuntu 24.04.5 LTS (noble) | 6.76-1ubuntu0.1 | [libwww-perl 6.76-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libwww-perl-6.76-1ubuntu0.1.md) | May 12, 2026 |
| Linux | libwww-perl Ubuntu 25.10 (questing) | 6.78-1ubuntu0.1 | [libwww-perl 6.78-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libwww-perl-6.78-1ubuntu0.1.md) | May 12, 2026 |
| Linux | libwww-perl Ubuntu 26.04.1 LTS (resolute) | 6.81-1ubuntu0.1 | [libwww-perl 6.81-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libwww-perl-6.81-1ubuntu0.1.md) | May 12, 2026 |
| Linux | perl-libwww-perl amzn 2023 | 6.58-1.amzn2023.0.3 | [ALAS2023-2026-1764](https://patchblox.com/security/data/fix/linux/alas2023-2026-1764.md) | May 25, 2026 |
| Linux | perl-libwww-perl opensuse-leap 16.0 | 6.770.0-160000.3.1 | [OPENSUSE-SU-2026:21045-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21045-1.md) | Jun 24, 2026 |
| Linux | perl-libwww-perl sles 15.7 | 6.31-150000.3.3.1 | [SUSE-SU-2026:2962-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2962-1.md) | Jul 14, 2026 |
| Linux | perl-libwww-perl sles 16.0 | 6.770.0-160000.3.1 | [SUSE-SU-2026:22353-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22353-1.md) | Jun 24, 2026 |
| Linux | perl-libwww-perl-tests amzn 2023 | 6.58-1.amzn2023.0.3 | [ALAS2023-2026-1764](https://patchblox.com/security/data/fix/linux/alas2023-2026-1764.md) | May 25, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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