Vulnerability · Published May 12, 2026 · Assigned by CPANSec
CVE-2026-8368LWP::UserAgent versions before 6.83 for Perl leak Authorization and Proxy-Authorization headers on cross-origin redirects
Medium 6.5
In plain English
A medium-severity security flaw in LWP::UserAgent from OALDERS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libwww-perl | no fix listed | DEBIAN-CVE-2026-8368 |
| Debian:13 | libwww-perl | no fix listed | DEBIAN-CVE-2026-8368 |
| Debian:14 | libwww-perl | 6.83-1 | DEBIAN-CVE-2026-8368 |
| Ubuntu:22.04:LTS | libwww-perl | 6.61-1ubuntu0.1 | UBUNTU-CVE-2026-8368 |
| Ubuntu:22.04:LTS | libwww-perl | 6.61-1ubuntu0.1 | USN-8378-1 |
| Ubuntu:24.04:LTS | libwww-perl | 6.76-1ubuntu0.1 | USN-8378-1 |
| Ubuntu:24.04:LTS | libwww-perl | 6.76-1ubuntu0.1 | UBUNTU-CVE-2026-8368 |
| Ubuntu:25.10 | libwww-perl | 6.78-1ubuntu0.1 | USN-8378-1 |
| Ubuntu:25.10 | libwww-perl | 6.78-1ubuntu0.1 | UBUNTU-CVE-2026-8368 |
| Ubuntu:26.04:LTS | libwww-perl | 6.81-1ubuntu0.1 | USN-8378-1 |
| Ubuntu:26.04:LTS | libwww-perl | 6.81-1ubuntu0.1 | UBUNTU-CVE-2026-8368 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| OALDERS | LWP::UserAgent | 0 – before 6.83 |
Weakness: CWE-522 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/libwww-perl/libwww-perl/commit/9c4aeb6f2dd32f2b7eaf2d7827cade31ea6cb2c6.patch patch
- https://metacpan.org/release/OALDERS/libwww-perl-6.83/changes release-notes
- https://github.com/libwww-perl/libwww-perl/pull/512 issue-tracking
- https://github.com/libwww-perl/libwww-perl/pull/284 related
- http://www.openwall.com/lists/oss-security/2026/05/12/7