CVE-2025-14523 Libsoup: libsoup: duplicate host header handling causes host-parsing discrepancy (first- vs last-value wins)

High 8.2 Published Updated

Attackers can exploit Host header discrepancies in libsoup to bypass access controls or poison caches via request smuggling.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2025-14523?

CVE-2025-14523 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 11 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost confusion where a proxy routes a request to one backend but the backend interprets it as destined for another host. This discrepancy enables request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker supplies duplicate Host headers.

Weakness: CWE-444

Which versions are affected by CVE-2025-14523?

Linux distribution packages (40)
libsoup3-doc AlmaLinux:10All versions3.6.5-3.el10_1.8
libsoup AlmaLinux:8All versions2.62.3-11.el8_10
libsoup-devel AlmaLinux:8All versions2.62.3-11.el8_10
libsoup AlmaLinux:9All versions2.72.0-12.el9_7.3
libsoup-devel AlmaLinux:9All versions2.72.0-12.el9_7.3
libsoup3 Red Hat:enterprise_linux:10.1All versions0:3.6.5-3.el10_1.8
libsoup3-debuginfo Red Hat:enterprise_linux:10.1All versions0:3.6.5-3.el10_1.8
libsoup3-debugsource Red Hat:enterprise_linux:10.1All versions0:3.6.5-3.el10_1.8
libsoup3-devel Red Hat:enterprise_linux:10.1All versions0:3.6.5-3.el10_1.8
libsoup3-doc Red Hat:enterprise_linux:10.1All versions0:3.6.5-3.el10_1.8
libsoup-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:2.62.3-11.el8_10
libsoup-debugsource Red Hat:enterprise_linux:8::appstreamAll versions0:2.62.3-11.el8_10
libsoup-devel Red Hat:enterprise_linux:8::appstreamAll versions0:2.62.3-11.el8_10
spice-client-win Red Hat:enterprise_linux:8::appstreamAll versions0:8.10-6.el8_10.1
spice-client-win-x64 Red Hat:enterprise_linux:8::appstreamAll versions0:8.10-6.el8_10.1
spice-client-win-x86 Red Hat:enterprise_linux:8::appstreamAll versions0:8.10-6.el8_10.1
libsoup Red Hat:enterprise_linux:8::baseosAll versions0:2.62.3-11.el8_10
libsoup-debuginfo Red Hat:enterprise_linux:8::baseosAll versions0:2.62.3-11.el8_10
libsoup-debugsource Red Hat:enterprise_linux:8::baseosAll versions0:2.62.3-11.el8_10
libsoup Red Hat:enterprise_linux:9::appstreamAll versions0:2.72.0-12.el9_7.3
libsoup-debuginfo Red Hat:enterprise_linux:9::appstreamAll versions0:2.72.0-12.el9_7.3
libsoup-debugsource Red Hat:enterprise_linux:9::appstreamAll versions0:2.72.0-12.el9_7.3
libsoup-devel Red Hat:enterprise_linux:9::appstreamAll versions0:2.72.0-12.el9_7.3
libsoup3 Red Hat:enterprise_linux_eus:10.0All versions0:3.6.5-3.el10_0.11
libsoup3-debuginfo Red Hat:enterprise_linux_eus:10.0All versions0:3.6.5-3.el10_0.11
libsoup3-debugsource Red Hat:enterprise_linux_eus:10.0All versions0:3.6.5-3.el10_0.11
libsoup3-devel Red Hat:enterprise_linux_eus:10.0All versions0:3.6.5-3.el10_0.11
libsoup3-doc Red Hat:enterprise_linux_eus:10.0All versions0:3.6.5-3.el10_0.11
libsoup-debuginfo Red Hat:rhel_aus:8.2::appstreamAll versions0:2.62.3-1.el8_2.7
libsoup-debugsource Red Hat:rhel_aus:8.2::appstreamAll versions0:2.62.3-1.el8_2.7
libsoup-devel Red Hat:rhel_aus:8.2::appstreamAll versions0:2.62.3-1.el8_2.7
spice-client-win Red Hat:rhel_aus:8.2::appstreamAll versions0:8.10-6.el8_2.1
spice-client-win-x64 Red Hat:rhel_aus:8.2::appstreamAll versions0:8.10-6.el8_2.1
spice-client-win-x86 Red Hat:rhel_aus:8.2::appstreamAll versions0:8.10-6.el8_2.1
libsoup Red Hat:rhel_aus:8.2::baseosAll versions0:2.62.3-1.el8_2.7
libsoup-debuginfo Red Hat:rhel_aus:8.2::baseosAll versions0:2.62.3-1.el8_2.7
libsoup-debugsource Red Hat:rhel_aus:8.2::baseosAll versions0:2.62.3-1.el8_2.7
libsoup-debuginfo Red Hat:rhel_aus:8.4::appstreamAll versions0:2.62.3-2.el8_4.7
libsoup-debugsource Red Hat:rhel_aus:8.4::appstreamAll versions0:2.62.3-2.el8_4.7
libsoup-devel Red Hat:rhel_aus:8.4::appstreamAll versions0:2.62.3-2.el8_4.7

How do I fix CVE-2025-14523?

Apply the vendor's patch.

Is CVE-2025-14523 being exploited?

There is no known exploitation of CVE-2025-14523 in the wild and no public exploit code.

Sources

Also known as ALSA-2026:0421, ALSA-2026:0422, ALSA-2026:0423, AZL-72292, AZL-72302, CLSA-2026-1768555539 and 36 more.

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