CVE-2025-4945 | Libsoup: integer overflow in cookie expiration date handling in libsoup

A flaw was found in the cookie parsing logic of the libsoup HTTP library, used in GNOME applications and other software. The vulnerability arises when processing the expiration date of cookies, where a specially crafted value can trigger an integer overflow. This may result in undefined behavior, allowing an attacker to bypass cookie expiration logic, causing persistent or unintended cookie behavior. The issue stems from improper validation of large integer inputs during date arithmetic operations within the cookie parsing routines.

Published: 2025-05-19 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-4945 is rated Low Risk (28.5/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.50%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-4945

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.30% 0.50% +0.20%
2 2026-03-21 0.96% 0.30% -0.67%
3 2026-03-15 0.96%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-4945

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.7 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 1.4 [email protected]

Weakness enumeration for CVE-2025-4945

OS Trackers for CVE-2025-4945

vendor priority summary link
debian not yet assigned CVE-2025-4945 not yet assigned priority: Debian including 2 source packages (libsoup2.4, libsoup3), 7 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 3. https://security-tracker.debian.org/tracker/CVE-2025-4945
redhat low https://access.redhat.com/security/cve/CVE-2025-4945
suse low CVE-2025-4945 severity low: SUSE including 52 source package names (curl-8.14.1-slfo.1.1_4.1, latest:curl-8.14.1-slfo.1.1_4.1, …), 99 product×package rows across 32 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (32 product lines)): Fixed 99. https://www.suse.com/security/cve/CVE-2025-4945/
ubuntu medium CVE-2025-4945 medium priority: Ubuntu including 2 source packages (libsoup2.4, libsoup3), 16 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream, xenial): released 11, ignored 2, needs-triage 2, DNE 1. https://ubuntu.com/security/CVE-2025-4945

Affected software / configurations for CVE-2025-4945

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-4945

URL Tags
https://access.redhat.com/errata/RHSA-2025:19713
https://access.redhat.com/errata/RHSA-2025:19714
https://access.redhat.com/errata/RHSA-2025:19720
https://access.redhat.com/errata/RHSA-2025:20959
https://access.redhat.com/errata/RHSA-2025:21032
https://access.redhat.com/errata/RHSA-2025:21655
https://access.redhat.com/errata/RHSA-2025:21656
https://access.redhat.com/errata/RHSA-2025:21657
https://access.redhat.com/errata/RHSA-2025:21664
https://access.redhat.com/errata/RHSA-2025:21665
https://access.redhat.com/errata/RHSA-2025:21666
https://access.redhat.com/errata/RHSA-2025:21772
https://access.redhat.com/errata/RHSA-2025:22013
https://access.redhat.com/security/cve/CVE-2025-4945
https://bugzilla.redhat.com/show_bug.cgi?id=2367175
https://gitlab.gnome.org/GNOME/libsoup/-/issues/448
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