How severe is CVE-2025-4035?

CVE-2025-4035 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2025-4035 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-4035?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-4035 have an EU (EUVD) identifier?

Yes. CVE-2025-4035 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15014.

When was CVE-2025-4035 published?

CVE-2025-4035 was published on 2025-04-29 and last updated on 2026-06-30.

CVE-2025-4035

CVE-2025-4035 is a medium-severity vulnerability with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-178.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-15014
Weakness: CWE-178
Published: 2025-04-29
Last modified: 2026-06-30

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.

Frequently asked questions

What is CVE-2025-4035?: 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.
How severe is CVE-2025-4035?: CVE-2025-4035 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2025-4035 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-4035?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-4035 have an EU (EUVD) identifier?: Yes. CVE-2025-4035 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-15014.
When was CVE-2025-4035 published?: CVE-2025-4035 was published on 2025-04-29 and last updated on 2026-06-30.

References

Other CWE-178 vulnerabilities

CVE-2026-54763 — Critical (CVSS 10.0): Traefik is an HTTP reverse proxy and load balancer. Prior to v2.11.51, v3.6.22, and v3.7.6, Traefik's BasicAuth,…
CVE-2026-40453 — Critical (CVSS 9.9): The fix for CVE-2025-27636 added setLowerCase(true) to HttpHeaderFilterStrategy so that case-variant header names such…
CVE-2026-47323 — Critical (CVSS 9.8): Camel-CXF and Camel-Knative Message Header Injection via Missing Inbound Filtering The CXF and Knative…
CVE-2024-5699 — Critical (CVSS 9.8): In violation of spec, cookie prefixes such as `__Secure` were being ignored if they were not correctly capitalized - by…
CVE-2023-3545 — Critical (CVSS 9.8): Improper sanitisation in `main/inc/lib/fileUpload.lib.php` in Chamilo LMS <= v1.11.20 on Windows and Apache…
CVE-2022-29604 — Critical (CVSS 9.8): An issue was discovered in ONOS 2.5.1. An intent with an uppercase letter in a device ID shows the CORRUPT state, which…

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