# CVE-2026-73270: httpd mod_auth directory protection bypassed by request path casing on case-insensitive filesystems

> Remote attackers can bypass mod_auth directory protection and read protected files on case-insensitive filesystems by exploiting case sensitivity flaws in path matching.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/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:** 1 Sep 2026
- **Updated:** 8 Sep 2026
- **Also known as:** AZL-98484, DEBIAN-CVE-2026-73270, EEF-CVE-2026-73270, GHSA-mh78-93cr-jx8f, UBUNTU-CVE-2026-73270

## What is CVE-2026-73270?

CVE-2026-73270 is a high-severity authentication bypass vulnerability in Erlang OTP, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Handling of Case Sensitivity vulnerability in Erlang/OTP inets httpd allows a remote unauthenticated attacker to read files inside a mod_auth protected directory by requesting them with different casing, on deployments whose filesystem is case-insensitive.

mod_auth:secret_path/3 decides whether a resolved filesystem path lies inside a protected directory block by running the configured directory path through re:run/3 without the caseless option. A request for /secret/file against a directory configured as /Secret therefore does not match, so the request is treated as unprotected and no authentication challenge is issued, while the filesystem resolves the differently cased path to the same file and mod_get serves it. Deployments on case-sensitive filesystems are unaffected, because there the filesystem itself rejects the mismatched casing.

This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

Weakness: CWE-178 (Improper Handling of Case Sensitivity)

## Which versions are affected by CVE-2026-73270?


## How do I fix CVE-2026-73270?

Upgrade to a fixed version.

## Is CVE-2026-73270 being exploited?

There is no known exploitation of CVE-2026-73270 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73270 and fix it if it is affected.

What it is: CVE-2026-73270 is a high-severity authentication bypass vulnerability in Erlang OTP, published on 1 Sep 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-2026-73270 in the wild and no public exploit code.

Affected product: Erlang OTP. 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-2026-73270/ (Markdown: https://insights.sbomify.com/CVE-2026-73270/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73270
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73270
- OSV: https://osv.dev/vulnerability/CVE-2026-73270

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73270/
Summaries are generated and may contain mistakes; the official description above is the record.