# CVE-2026-27654: NGINX ngx_http_dav_module vulnerability

> Attackers can trigger a buffer overflow in NGINX DAV module, causing worker termination or file name modification outside the document root.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/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:** 24 Mar 2026
- **Updated:** 15 Jul 2026
- **Also known as:** ALPINE-CVE-2026-27654, AZL-80774, BELL-CVE-2026-27654, BIT-nginx-2026-27654, BIT-nginx-gateway-2026-27654, CLSA-2026-1776766448, CLSA-2026-1777396606, CLSA-2026-1777883924, CLSA-2026-1777884034, DEBIAN-CVE-2026-27654, ECHO-3bda-1571-9bc1, GHSA-6r46-2qjx-j5j3, MINI-4gpg-qpg2-7qhf, MINI-h338-7ggm-f6m3, MINI-h3r2-g72c-fm55, MINI-w836-23vv-576m, ROOT-OS-ALPINE-315-CVE-2026-27654, ROOT-OS-ALPINE-320-CVE-2026-27654, ROOT-OS-ALPINE-321-CVE-2026-27654, UBUNTU-CVE-2026-27654

## What is CVE-2026-27654?

CVE-2026-27654 is a high-severity memory corruption vulnerability in F5 NGINX Open Source, published on 24 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

NGINX Open Source and NGINX Plus have a vulnerability in the ngx_http_dav_module module that might allow an attacker to trigger a buffer overflow to the NGINX worker process; this vulnerability may result in termination of the NGINX worker process or modification of source or destination file names outside the document root. This issue affects NGINX Open Source and NGINX Plus when the configuration file uses DAV module MOVE or COPY methods, prefix location (nonregular expression location configuration), and alias directives. The integrity impact is constrained because the NGINX worker process user has low privileges and does not have access to the entire system. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-27654?

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 0.5.13 | 1.28.3, 1.29.7 |
| `nginx-gateway` | Bitnami | From 0.5.13 | 1.28.3, 1.29.7 |

Products: F5 Nginx Open Source, F5 Nginx Plus.

## How do I fix CVE-2026-27654?

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

## Is CVE-2026-27654 being exploited?

There is no known exploitation of CVE-2026-27654 in the wild and no public exploit code.

Public exploit code:

- NGINX `ngx_http_dav_module` Heap Buffer Overflow via `size_t` Underflow (Remote DoS / Potential RCE) (github_poc): https://github.com/JohannesLks/CVE-2026-27654
- Proof-of-Concept and technical analysis for CVE-2026-27654, a heap-based buffer overflow vulnerability in the NGINX HTTP WebDAV module, including root cause analysis, reproduction, and mitigation. (github_poc): https://github.com/Debajyoti0-0/CVE-2026-27654-PoC
- Обзор n-day уязвимости на русском языке. (github_poc): https://github.com/dead-lamer/CVE-2026-27654

## Other vulnerabilities in F5 NGINX Open Source

- [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)
- [CVE-2024-24990](https://insights.sbomify.com/CVE-2024-24990/): NGINX HTTP/3 QUIC vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27654 and fix it if it is affected.

What it is: CVE-2026-27654 is a high-severity memory corruption vulnerability in F5 NGINX Open Source, published on 24 Mar 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-2026-27654 in the wild and no public exploit code.

Affected packages and fixed versions:
- nginx (Bitnami): affected from 0.5.13; fixed in 1.28.3, 1.29.7
- nginx-gateway (Bitnami): affected from 0.5.13; 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-2026-27654/ (Markdown: https://insights.sbomify.com/CVE-2026-27654/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27654
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27654
- OSV: https://osv.dev/vulnerability/CVE-2026-27654

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27654/
Summaries are generated and may contain mistakes; the official description above is the record.