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CVE-2025-4035

Libsoup: cookie domain validation bypass via uppercase characters in libsoup

Products / packages Red Hat Enterprise Linux 10 · Red Hat Enterprise Linux 6 · Red Hat Enterprise Linux 7 · 2 more

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Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 15/11/2026, 03:00:33 UTC
redhat · CVSS:3.1 · 4.3
Assessment vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Severity

medium4.3

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Exploit reference published

Source-linked evidence; not proof of attacks in the wild or independent validation.

Remediation

Fix status not established

No structured fix or guidance is available here. Check the latest publisher advisory.

What this means

Libsoup has a flaw that allows cookies to be set for public suffix domains with uppercase characters, potentially leading to integrity issues. The affected products include various versions of Red Hat Enterprise Linux. The weakness is due to improper handling of case sensitivity.

Summarized by @cf/meta/llama-3.3-70b-instruct-fp8-fast. Verify details against the original sources.

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Red Hat · redhat

Red Hat Enterprise Linux 10

1 range
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

0:3.6.5-3.el10_0.6 → before *

rpm versions

unknown

Other versions: affected

Product identifiers (CPE)cpe:/o:redhat:enterprise_linux:10.0

Red Hat · redhat

Red Hat Enterprise Linux 6

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/o:redhat:rhel_els:6

Red Hat · redhat

Red Hat Enterprise Linux 7

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/o:redhat:rhel_els:7

Red Hat · redhat

Red Hat Enterprise Linux 8

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:enterprise_linux:8

Red Hat · redhat

Red Hat Enterprise Linux 9

0 ranges
redhat version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

unaffected

unknown

Other versions: affected

Product identifiers (CPE)cpe:/a:redhat:enterprise_linux:9
Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

The sources identify public exploit references. We have not independently tested them; their availability does not establish exploitation in the wild.

gitlab.gnome.org/GNOME/libsoup/-/work_items/443 ↗Attributed to CISA-ADP

Original source description

Read the full publisher description

A flaw was found in libsoup. When handling cookies, libsoup clients mistakenly allow cookies to be set for public suffix domains if the domain contains at least two components and includes an uppercase character. This bypasses public suffix protections and could allow a malicious website to set cookies for domains it does not own, potentially leading to integrity issues such as session fixation.

References

5 sources
access.redhat.com/errata/RHSA-2025:8128
Vendor advisoryredhat
access.redhat.com/security/cve/CVE-2025-4035
Security advisoryredhat
bugzilla.redhat.com/show_bug.cgi
Source referenceredhat
gitlab.gnome.org/GNOME/libsoup/-/issues/443
Source referenceredhat
gitlab.gnome.org/GNOME/libsoup/-/work_items/443
Public exploit referenceCISA-ADP

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification
Additional publishers

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2025-4035

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Underlying weaknesses

The source’s classification of what caused the vulnerability.

CWE-178 ↗

Improper Handling of Case Sensitivity

redhat

Related →
Contributing organizations · 2
redhat

Assigning organization

2026-11-05
CISA-ADP

Additional data publisher

2026-06-30

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

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Large field values are marked as truncated previews. Original source snapshots remain retained.