# CVE-2025-23419: TLS Session Resumption Vulnerability > Attackers can bypass client certificate authentication on NGINX servers sharing an IP/port by exploiting TLS session resumption mechanisms. - **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 5 Feb 2025 - **Updated:** 23 Jan 2026 - **Also known as:** ALPINE-CVE-2025-23419, AZL-56483, AZL-56492, BELL-CVE-2025-23419, BIT-nginx-2025-23419, BIT-nginx-gateway-2025-23419, CLEANSTART-2026-AH14846, CLSA-2025-1752516250, DEBIAN-CVE-2025-23419, GHSA-84xh-pwc6-7g4g, MGASA-2025-0051, OESA-2025-1134, RHSA-2025:7331, UBUNTU-CVE-2025-23419, USN-7285-1, USN-7285-2, openSUSE-SU-2025:14737-1 ## What is CVE-2025-23419? CVE-2025-23419 is a medium-severity authentication bypass vulnerability in Debian Debian Linux, published on 5 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description When multiple server blocks are configured to share the same IP address and port, an attacker can use session resumption to bypass client certificate authentication requirements on these servers. This vulnerability arises when TLS Session Tickets https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key are used and/or the SSL session cache https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache are used in the default server and the default server is performing client certificate authentication.   Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. Weakness: CWE-863 (Incorrect Authorization) ## Which versions are affected by CVE-2025-23419? 2 open source packages ship an affected version, including nginx and nginx-gateway. It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `nginx` | Bitnami | From 1.11.4 | 1.26.3, 1.27.4 | | `nginx-gateway` | Bitnami | From 1.11.4 | 1.26.3, 1.27.4 | | `nginx` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-all-modules` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-core` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-core-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-filesystem` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-image-filter` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-image-filter-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-perl` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-perl-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-xslt-filter` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-xslt-filter-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-mail` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-mail-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-stream` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-mod-stream-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 2:1.20.1-22.el9 | | `nginx-core-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-debugsource` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-mod-devel` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-image-filter-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-perl-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-mod-http-xslt-filter-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-mod-mail-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx-mod-stream-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 2:1.20.1-22.el9 | | `nginx` | openSUSE:Tumbleweed | All versions | 1.27.4-1.1 | Products: Debian Debian Linux, F5 Nginx, F5 Nginx Plus. ## How do I fix CVE-2025-23419? Upgrade nginx to a fixed version for your release line: 1.26.3 or 1.27.4. ## Is CVE-2025-23419 being exploited? There is no known exploitation of CVE-2025-23419 in the wild and no public exploit code. Public exploit code: - Script em python scanner safe-check da CVE-2025-23419 (github_poc): https://github.com/harley-ghostie/safe-check-CVE-2025-23419 - https://github.com/xitexploiter96-dot/CVE-2025-23419 (github_poc): https://github.com/xitexploiter96-dot/CVE-2025-23419 ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-23419 and fix it if it is affected. What it is: CVE-2025-23419 is a medium-severity authentication bypass vulnerability in Debian Debian Linux, published on 5 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-23419 in the wild and no public exploit code. Affected packages and fixed versions: - nginx (Bitnami): affected from 1.11.4; fixed in 1.26.3, 1.27.4 - nginx-gateway (Bitnami): affected from 1.11.4; fixed in 1.26.3, 1.27.4 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-2025-23419/ (Markdown: https://insights.sbomify.com/CVE-2025-23419/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-23419 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-23419 - OSV: https://osv.dev/vulnerability/CVE-2025-23419 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-23419/ Summaries are generated and may contain mistakes; the official description above is the record.