# CVE-2025-14523: Libsoup: libsoup: duplicate host header handling causes host-parsing discrepancy (first- vs last-value wins) > Attackers can exploit Host header discrepancies in libsoup to bypass access controls or poison caches via request smuggling. - **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 Dec 2025 - **Updated:** 29 Jun 2026 - **Also known as:** ALSA-2026:0421, ALSA-2026:0422, ALSA-2026:0423, AZL-72292, AZL-72302, CLSA-2026-1768555539, CLSA-2026-1768566531, CLSA-2026-1769598671, CLSA-2026-1769598900, CLSA-2026-1769687040, DEBIAN-CVE-2025-14523, ECHO-60b1-7d52-5aa4, GHSA-4qpp-gxm3-h9vw, RHSA-2026:0421, RHSA-2026:0422, RHSA-2026:0423, RHSA-2026:0836, RHSA-2026:0867, RHSA-2026:0868, RHSA-2026:0905, RHSA-2026:0906, RHSA-2026:0907, RHSA-2026:0908, RHSA-2026:0909, RHSA-2026:0911, RHSA-2026:0925, RHSA-2026:1509, RHSA-2026:1569, RHSA-2026:1570, RHSA-2026:1571, RHSA-2026:1572, RLSA-2026:0421, RLSA-2026:0422, RLSA-2026:0423, RLSA-2026:1509, ROOT-OS-DEBIAN-12-CVE-2025-14523, ROOT-OS-DEBIAN-13-CVE-2025-14523, SUSE-SU-2026:0123-1, SUSE-SU-2026:20053-1, UBUNTU-CVE-2025-14523, openSUSE-SU-2026:10023-1, openSUSE-SU-2026:10024-1 ## 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 (Inconsistent Interpretation of HTTP Requests) ## Which versions are affected by CVE-2025-14523? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `libsoup3-doc` | AlmaLinux:10 | All versions | 3.6.5-3.el10_1.8 | | `libsoup` | AlmaLinux:8 | All versions | 2.62.3-11.el8_10 | | `libsoup-devel` | AlmaLinux:8 | All versions | 2.62.3-11.el8_10 | | `libsoup` | AlmaLinux:9 | All versions | 2.72.0-12.el9_7.3 | | `libsoup-devel` | AlmaLinux:9 | All versions | 2.72.0-12.el9_7.3 | | `libsoup3` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.6.5-3.el10_1.8 | | `libsoup3-debuginfo` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.6.5-3.el10_1.8 | | `libsoup3-debugsource` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.6.5-3.el10_1.8 | | `libsoup3-devel` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.6.5-3.el10_1.8 | | `libsoup3-doc` | Red Hat:enterprise_linux:10.1 | All versions | 0:3.6.5-3.el10_1.8 | | `libsoup-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:2.62.3-11.el8_10 | | `libsoup-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:2.62.3-11.el8_10 | | `libsoup-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:2.62.3-11.el8_10 | | `spice-client-win` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.10-6.el8_10.1 | | `spice-client-win-x64` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.10-6.el8_10.1 | | `spice-client-win-x86` | Red Hat:enterprise_linux:8::appstream | All versions | 0:8.10-6.el8_10.1 | | `libsoup` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.62.3-11.el8_10 | | `libsoup-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.62.3-11.el8_10 | | `libsoup-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:2.62.3-11.el8_10 | | `libsoup` | Red Hat:enterprise_linux:9::appstream | All versions | 0:2.72.0-12.el9_7.3 | | `libsoup-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:2.72.0-12.el9_7.3 | | `libsoup-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:2.72.0-12.el9_7.3 | | `libsoup-devel` | Red Hat:enterprise_linux:9::appstream | All versions | 0:2.72.0-12.el9_7.3 | | `libsoup3` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:3.6.5-3.el10_0.11 | | `libsoup3-debuginfo` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:3.6.5-3.el10_0.11 | | `libsoup3-debugsource` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:3.6.5-3.el10_0.11 | | `libsoup3-devel` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:3.6.5-3.el10_0.11 | | `libsoup3-doc` | Red Hat:enterprise_linux_eus:10.0 | All versions | 0:3.6.5-3.el10_0.11 | | `libsoup-debuginfo` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:2.62.3-1.el8_2.7 | | `libsoup-debugsource` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:2.62.3-1.el8_2.7 | | `libsoup-devel` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:2.62.3-1.el8_2.7 | | `spice-client-win` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:8.10-6.el8_2.1 | | `spice-client-win-x64` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:8.10-6.el8_2.1 | | `spice-client-win-x86` | Red Hat:rhel_aus:8.2::appstream | All versions | 0:8.10-6.el8_2.1 | | `libsoup` | Red Hat:rhel_aus:8.2::baseos | All versions | 0:2.62.3-1.el8_2.7 | | `libsoup-debuginfo` | Red Hat:rhel_aus:8.2::baseos | All versions | 0:2.62.3-1.el8_2.7 | | `libsoup-debugsource` | Red Hat:rhel_aus:8.2::baseos | All versions | 0:2.62.3-1.el8_2.7 | | `libsoup-debuginfo` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:2.62.3-2.el8_4.7 | | `libsoup-debugsource` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:2.62.3-2.el8_4.7 | | `libsoup-devel` | Red Hat:rhel_aus:8.4::appstream | All versions | 0:2.62.3-2.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. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-14523 and fix it if it is affected. What it is: 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. Exploitation: There is no known exploitation of CVE-2025-14523 in the wild and no public exploit code. Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-14523/ (Markdown: https://insights.sbomify.com/CVE-2025-14523/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-14523 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-14523 - OSV: https://osv.dev/vulnerability/CVE-2025-14523 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-14523/ Summaries are generated and may contain mistakes; the official description above is the record.