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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 6 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libsoup | No fix yet | — |
| Debian 13 | libsoup3 +1 | No fix yet | — |
| Debian 12 | libsoup3 +1 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libsoup3 +1 | No fix yet | — |
| Ubuntu 26.04 LTS | libsoup3 | No fix yet | — |
| Ubuntu 25.10 | libsoup3 +1 | No fix yet | — |
| Ubuntu 24.04 LTS | libsoup3 +1 | No fix yet | — |
| Ubuntu 22.04 LTS | libsoup2.4 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | libsoup2.4 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | libsoup3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | libsoup2.4 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | libsoup2.4 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | libsoup2.4 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | libsoup3 +2 | 3.6.5-3.el10_0.6 | RHSA-2025:8128 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | libsoup3-doc | 3.6.5-3.el10_0.6 | ALSA-2025:8128 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | libsoup3 | 3.6.5-3.el10_0.6 | RLSA-2025:8128 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libsoup | No fix yet | — |
| Azure Linux 2 (CBL-Mariner) | libsoup | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | libsoup3 +2 | 3.6.5-3.el10_0.6 | ELSA-2025-8128 |
Advisories 4
- ALSA-2025:8128 Important: libsoup3 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:8128 Red Hat Security Advisory: libsoup3 security update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RLSA-2025:8128 Important: libsoup3 security update Rocky Linux Security Advisories · Oct 8, 2025
- ELSA-2025-8128 Important: libsoup3 security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jun 26, 2025
References
- RHSA-2025:8128 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2025-4035 vdb-entry
- RHBZ#2362651 issue-tracking
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/443