Is CVE-2026-12547 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-12547 being exploited in the wild.

How severe is CVE-2026-12547?

Low severity, with a CVSS score of 3.4, published 21 July 2026.

Which products and versions are affected?

Gnome Libsoup Red Hat Enterprise Linux 10.

Is there a fix for CVE-2026-12547?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-12547 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-12547?

Check whether you run Gnome Libsoup 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.

CVE-2026-12547: GNOME libsoup information disclosure in SoupAuthManager proxy credential handling

CVE-2026-12547 · Severity: low · CVSS 3.4 · Published 2026-07-21

libsoup is a networking library used by many Linux applications to handle web requests. A flaw in how it manages proxy server authentication allows sensitive login credentials intended for one proxy server to be accidentally sent to a different proxy server if the system's network configuration changes. This could allow an attacker who controls a secondary proxy server to capture enterprise credentials when a user switches networks or updates their settings.

Technologies: Gnome Libsoup. Vendors: Gnome.

Quick answers

Is CVE-2026-12547 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-12547 being exploited in the wild.
How severe is CVE-2026-12547?: Low severity, with a CVSS score of 3.4, published 21 July 2026.
Which products and versions are affected?: Gnome Libsoup Red Hat Enterprise Linux 10.
Is there a fix for CVE-2026-12547?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-12547 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-12547?: Check whether you run Gnome Libsoup 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

A vulnerability exists in libsoup's SoupAuthManager where proxy authentication state is cached globally rather than being scoped to a specific proxy authority (host:port). When a session's proxy configuration is updated (e.g., via system settings or WPAD) after an initial authentication has occurred, the library incorrectly attaches the cached 'Proxy-Authorization' header from the previous proxy to requests sent to the new proxy. An attacker who can influence proxy settings or provide a malicious proxy can capture these leaked credentials. The issue is tracked in libsoup's internal work items and affects versions used in Red Hat Enterprise Linux 10 and other GNOME-based environments.

Affected products

Red Hat libsoup3 Red Hat Enterprise Linux 10
GNOME libsoup

Timeline

2026-01-25: disclosed: Vulnerability reported via YesWeHack
2026-06-17: other: Bug report opened in Red Hat Bugzilla
2026-07-21: advisory: CVE published to NVD

References

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