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CVE-2025-4035· NVD / CVE Program· CNA redhat

Libsoup: cookie domain validation bypass via uppercase characters in libsoup

Noroxi assessment

Priority: Monitor (action score 17/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.43% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: azl3 libsoup 3.4.4-16 on Azure Linux 3.0 Release Notes; azl3 libsoup 3.4.4-17 on Azure Linux 3.0 Release Notes; cbl2 libsoup 3.0.4-13 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to azl3 libsoup 3.4.4-16 on Azure Linux 3.0 Release Notes; azl3 libsoup 3.4.4-17 on Azure Linux 3.0 Release Notes; cbl2 libsoup 3.0.4-13 on CBL-Mariner 2.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 4.3 · v3.1—No exploit Fix available
Published
Apr 29, 2025
Updated
Jun 30, 2026
EPSS
0.4% · 36th percentile

Report tools

JSON

Action score

17

Monitor

Low priority for now.

CVSS
17 / 40 · 4.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
4.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-4035

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat Enterprise Linux 10

    • 0:3.6.5-3.el10_0.6 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 8

    • all versionsaffected

  • Red Hat Red Hat Enterprise Linux 9

    • all versionsaffected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10libsoup3-docbefore 3.6.5-3.el10_0.63.6.5-3.el10_0.6
Debian:12libsoup2.4from 0—
Debian:12libsoup3from 0—
Red Hat:enterprise_linux:10.0libsoup3before 0:3.6.5-3.el10_0.60:3.6.5-3.el10_0.6
Red Hat:enterprise_linux:10.0libsoup3-debuginfobefore 0:3.6.5-3.el10_0.60:3.6.5-3.el10_0.6
Red Hat:enterprise_linux:10.0libsoup3-debugsourcebefore 0:3.6.5-3.el10_0.60:3.6.5-3.el10_0.6
Red Hat:enterprise_linux:10.0libsoup3-develbefore 0:3.6.5-3.el10_0.60:3.6.5-3.el10_0.6
Red Hat:enterprise_linux:10.0libsoup3-docbefore 0:3.6.5-3.el10_0.60:3.6.5-3.el10_0.6
Rocky Linux:10libsoup3before 0:3.6.5-3.el10_0.60:3.6.5-3.el10_0.6

Same product

red hat: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-10230Samba: command injection in wins server hook script
    52Plan
  • CVE-2026-4631Cockpit: cockpit: unauthenticated remote code execution due to ssh command-line argument injection
    42Plan
  • CVE-2026-76578Ipa: freeipa: freeipa: unauthenticated ldap client can obtain administrator credentials via the self-managed-token aci
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2024-10306Apr 23, 2025 · Mod_proxy_cluster: mod_proxy_cluster unauthorized mcmp requests
    21Monitor
  • ← EarlierCVE-2025-46421Apr 24, 2025 · Libsoup: information disclosure may leads libsoup client sends authorization header to a different host when being redirected by a server
    27Monitor
  • Later →CVE-2025-4373May 6, 2025 · Glib: buffer underflow on glib through glib/gstring.c via function g_string_insert_unichar
    19Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 libsoup 3.4.4-16 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 libsoup 3.4.4-17 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
cbl2 libsoup 3.0.4-13 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
almalinux:libsoup3-doc3.6.5-3.el10_0.6 · AlmaLinux:10Package registry (OSV)
red hat:libsoup30:3.6.5-3.el10_0.6 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:libsoup3-debuginfo0:3.6.5-3.el10_0.6 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:libsoup3-debugsource0:3.6.5-3.el10_0.6 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:libsoup3-devel0:3.6.5-3.el10_0.6 · Red Hat:enterprise_linux:10.0Package registry (OSV)
red hat:libsoup3-doc0:3.6.5-3.el10_0.6 · Red Hat:enterprise_linux:10.0Package registry (OSV)
rocky linux:libsoup30:3.6.5-3.el10_0.6 · Rocky Linux:10Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-178 · Improper Handling of Case Sensitivity

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records