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🛡️ CVE-2026-12547 on Ubuntu — libsoup2.4

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

SoupAuthManager caches proxy authentication credentials without scoping them to the proxy authority (host:port). When the proxy configuration changes (e.g., via system settings or WPAD), cached Proxy-Authorization headers from the previous proxy are sent to the new proxy, leaking credentials.

Distribution advisory

This page covers CVE-2026-12547 as tracked by Ubuntu, for the package libsoup2.4. No fixed version has been recorded for this distribution yet.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs administrative privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity none, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:N/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: High — administrative rights are needed first.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Changed — a successful attack reaches components beyond the vulnerable one.
  • Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
  • Integrity impact: None.
  • Availability impact: None.

Weakness class

UBUNTU-CVE-2026-12547 is classified as CWE-201: Insertion of Sensitive Information Into Sent Data. The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

Affected software

UBUNTU-CVE-2026-12547 is recorded against 2 packages.

  • libsoup2.4
  • libsoup3

Timeline and source

Published on 21 July 2026 and last revised on 29 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
gitlab.gnome.org (Report)
access.redhat.com (Report)
bugzilla.redhat.com (Report)

Other advisories for this package

libsoup2.4 has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-201: Insertion of Sensitive Information Into Sent Data) in other software:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:N/A:N
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-07-21
Updated 2026-08-20
Modified 2026-07-29
Fix URL N/A

Affected Packages

Software From version Fixed in
libsoup2.4 — —
libsoup3 — —

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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