# CVE-2026-28755: NGINX ngx_stream_ssl_module vulnerability

> Attackers can bypass certificate revocation checks in NGINX when specific SSL verification directives are enabled, allowing revoked certificates to be accepted.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/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:** 24 Mar 2026
- **Updated:** 24 Mar 2026
- **Also known as:** ALPINE-CVE-2026-28755, AZL-80783, BELL-CVE-2026-28755, BIT-nginx-2026-28755, BIT-nginx-gateway-2026-28755, DEBIAN-CVE-2026-28755, GHSA-hgfr-jmpr-2p89, MINI-ccc9-jq65-759j, MINI-crf7-qrcx-6f28, MINI-vhp7-mc5r-7p22, UBUNTU-CVE-2026-28755

## What is CVE-2026-28755?

CVE-2026-28755 is a medium-severity vulnerability in F5 NGINX Open Source, published on 24 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_stream_ssl_module module due to the improper handling of revoked certificates when configured with the ssl_verify_client on and ssl_ocsp on directives, allowing the TLS handshake to succeed even after an OCSP check identifies the certificate as revoked.   

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-2026-28755?

2 open source packages ship an affected version, including nginx and nginx-gateway. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nginx` | Bitnami | From 1.27.2 | 1.28.3, 1.29.7 |
| `nginx-gateway` | Bitnami | From 1.27.2 | 1.28.3, 1.29.7 |

Products: F5 Nginx Open Source, F5 Nginx Plus.

## How do I fix CVE-2026-28755?

Upgrade nginx to a fixed version for your release line: 1.28.3 or 1.29.7.

## Is CVE-2026-28755 being exploited?

There is no known exploitation of CVE-2026-28755 in the wild and no public exploit code.

Public exploit code:

- Covered CVEs: CVE-2026-28755, CVE-2026-42926, CVE-2026-9256, CVE-2026-42055, CVE-2026-42533 (github_poc): https://github.com/ChPratik/NGINX_2026_CVE_Bundle_CTI_Report

## Other vulnerabilities in F5 NGINX Open Source

- [CVE-2026-27654](https://insights.sbomify.com/CVE-2026-27654/): NGINX ngx_http_dav_module vulnerability (high 8.8)
- [CVE-2026-27651](https://insights.sbomify.com/CVE-2026-27651/): NGINX ngx_mail_auth_http_module vulnerability (high 8.7)
- [CVE-2026-27784](https://insights.sbomify.com/CVE-2026-27784/): NGINX ngx_http_mp4_module vulnerability (high 8.5)
- [CVE-2026-32647](https://insights.sbomify.com/CVE-2026-32647/): NGINX ngx_http_mp4_module vulnerability (high 8.5)
- [CVE-2024-24989](https://insights.sbomify.com/CVE-2024-24989/): NGINX HTTP/3 QUIC vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28755 and fix it if it is affected.

What it is: CVE-2026-28755 is a medium-severity vulnerability in F5 NGINX Open Source, published on 24 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-28755 in the wild and no public exploit code.

Affected packages and fixed versions:
- nginx (Bitnami): affected from 1.27.2; fixed in 1.28.3, 1.29.7
- nginx-gateway (Bitnami): affected from 1.27.2; fixed in 1.28.3, 1.29.7

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-2026-28755/ (Markdown: https://insights.sbomify.com/CVE-2026-28755/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28755
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28755
- OSV: https://osv.dev/vulnerability/CVE-2026-28755

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28755/
Summaries are generated and may contain mistakes; the official description above is the record.