# CVE-2026-1642: NGINX vulnerability > Man-in-the-middle attackers can inject plain text into TLS-proxied responses in NGINX when configured to proxy to upstream TLS servers. - **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Feb 2026 - **Updated:** 5 Feb 2026 - **Also known as:** ALPINE-CVE-2026-1642, ALSA-2026:3638, ALSA-2026:4235, ALSA-2026:4705, ALSA-2026:5581, ALSA-2026:5599, AZL-76706, AZL-76745, BELL-CVE-2026-1642, BIT-nginx-2026-1642, BIT-nginx-gateway-2026-1642, CLSA-2026-1773137907, CLSA-2026-1773312266, CLSA-2026-1782978575, CLSA-2026-1782979036, CLSA-2026-1782979343, CLSA-2026-1789729116, CLSA-2026-1789729184, CLSA-2026-1789729568, CLSA-2026-1789729730, CLSA-2026-1789729752, CLSA-2026-1789733488, DEBIAN-CVE-2026-1642, DSA-6131-1, ECHO-4b4a-86d2-9c71, GHSA-7chh-rv6q-8pp3, MGASA-2026-0033, MINI-3v8w-4cv3-vc5c, MINI-pf9m-p3w9-xvqr, MINI-rm2x-vwv9-wpwg, MINI-v473-p74c-f6j8, OESA-2026-1572, RHSA-2026:3638, RHSA-2026:4235, RHSA-2026:4705, RHSA-2026:5581, RHSA-2026:5599, RHSA-2026:6182, RHSA-2026:6234, RHSA-2026:6235, RHSA-2026:6302, RHSA-2026:6311, RHSA-2026:6407, RHSA-2026:6408, RHSA-2026:6427, RLSA-2026:3638, RLSA-2026:4235, RLSA-2026:4705, RLSA-2026:5581, ROOT-OS-ALPINE-315-CVE-2026-1642, ROOT-OS-ALPINE-320-CVE-2026-1642, ROOT-OS-ALPINE-321-CVE-2026-1642, UBUNTU-CVE-2026-1642, USN-8038-1, openSUSE-SU-2026:10158-1 ## What is CVE-2026-1642? CVE-2026-1642 is a high-severity vulnerability in F5 NGINX Open Source, published on 4 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability exists in NGINX OSS and NGINX Plus when configured to proxy to upstream Transport Layer Security (TLS) servers. An attacker with a man-in-the-middle (MITM) position on the upstream server side—along with conditions beyond the attacker's control—may be able to inject plain text data into the response from an upstream proxied server.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-349 (Acceptance of Extraneous Untrusted Data With Trusted Data) ## Which versions are affected by CVE-2026-1642? 2 open source packages ship an affected version, including nginx and nginx-gateway. It affects 5 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `nginx` | Bitnami | From 1.3.0 | 1.28.4, 1.29.5 | | `nginx-gateway` | Bitnami | From 1.3.0 | 1.29.5 | | `nginx-all-modules` | AlmaLinux:10 | All versions | 2:1.26.3-2.el10_1 | | `nginx-filesystem` | AlmaLinux:10 | All versions | 2:1.26.3-2.el10_1 | | `nginx` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-all-modules` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-filesystem` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-mod-devel` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-mod-http-image-filter` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-mod-http-perl` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-mod-http-xslt-filter` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-mod-mail` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx-mod-stream` | AlmaLinux:8 | All versions | 1:1.24.0-2.module_el8.10.0+4143+ec3e7d32.alma.1 | | `nginx` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-all-modules` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-all-modules` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-all-modules` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-core` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-core` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-core` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-filesystem` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-filesystem` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-filesystem` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-mod-devel` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-mod-devel` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-mod-devel` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-mod-http-image-filter` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-mod-http-image-filter` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-mod-http-image-filter` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-mod-http-perl` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-mod-http-perl` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-mod-http-perl` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-mod-http-xslt-filter` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-mod-http-xslt-filter` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-mod-http-xslt-filter` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | | `nginx-mod-mail` | AlmaLinux:9 | All versions | 1:1.24.0-5.module_el9.7.0+212+9d3c155a.1.alma.1 | | `nginx-mod-mail` | AlmaLinux:9 | All versions | 2:1.20.1-24.el9_7.1.alma.1 | | `nginx-mod-mail` | AlmaLinux:9 | All versions | 2:1.26.3-2.module_el9.7.0+215+8d94e91c | Products: F5 Nginx Gateway Fabric, F5 Nginx Ingress Controller, F5 Nginx Instance Manager, F5 Nginx Open Source, F5 Nginx Plus. ## How do I fix CVE-2026-1642? Upgrade nginx to a fixed version for your release line: 1.28.4 or 1.29.5. ## Is CVE-2026-1642 being exploited? There is no known exploitation of CVE-2026-1642 in the wild and no public exploit code. ## Other vulnerabilities in F5 NGINX Open Source - [CVE-2026-42533](https://insights.sbomify.com/CVE-2026-42533/): NGINX Map directive and Regex matching vulnerability (critical 9.2) - [CVE-2026-42530](https://insights.sbomify.com/CVE-2026-42530/): NGINX Open-Source ngx_http_v3_module vulnerability (critical 9.2) - [CVE-2026-60005](https://insights.sbomify.com/CVE-2026-60005/): NGINX ngx_http_slice_module vulnerability (high 8.8) - [CVE-2026-11311](https://insights.sbomify.com/CVE-2026-11311/): NGINX Gateway Fabric vulnerability (high 8.6) - [CVE-2026-50107](https://insights.sbomify.com/CVE-2026-50107/): NGINX Gateway Fabric vulnerability (high 8.6) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-1642 and fix it if it is affected. What it is: CVE-2026-1642 is a high-severity vulnerability in F5 NGINX Open Source, published on 4 Feb 2026. 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-2026-1642 in the wild and no public exploit code. Affected packages and fixed versions: - nginx (Bitnami): affected from 1.3.0; fixed in 1.28.4, 1.29.5 - nginx-gateway (Bitnami): affected from 1.3.0; fixed in 1.29.5 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-2026-1642/ (Markdown: https://insights.sbomify.com/CVE-2026-1642/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1642 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1642 - OSV: https://osv.dev/vulnerability/CVE-2026-1642 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-1642/ Summaries are generated and may contain mistakes; the official description above is the record.