# CVE-2025-9232: Out-of-bounds read in HTTP client no_proxy handling

> An attacker can cause a denial of service in applications using OpenSSL's HTTP client by triggering an out-of-bounds read via a crafted IPv6 URL when no_proxy is set.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Sep 2025
- **Updated:** 15 Oct 2026
- **Also known as:** ALPINE-CVE-2025-9232, AZL-67977, AZL-78588, BELL-CVE-2025-9232, DEBIAN-CVE-2025-9232, ECHO-b2f7-5a6b-fae1, GHSA-76r2-c3cg-f5r9, JLSEC-2026-268, MINI-25pm-87w9-mxxx, MINI-8ccc-42j9-wq95, MINI-8fpf-86mp-4g62, UBUNTU-CVE-2025-9232

## What is CVE-2025-9232?

CVE-2025-9232 is a medium-severity denial of service vulnerability in OpenSSL, published on 30 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Issue summary: An application using the OpenSSL HTTP client API functions may
trigger an out-of-bounds read if the 'no_proxy' environment variable is set and
the host portion of the authority component of the HTTP URL is an IPv6 address.

Impact summary: An out-of-bounds read can trigger a crash which leads to
Denial of Service for an application.

The OpenSSL HTTP client API functions can be used directly by applications
but they are also used by the OCSP client functions and CMP (Certificate
Management Protocol) client implementation in OpenSSL. However the URLs used
by these implementations are unlikely to be controlled by an attacker.

In this vulnerable code the out of bounds read can only trigger a crash.
Furthermore the vulnerability requires an attacker-controlled URL to be
passed from an application to the OpenSSL function and the user has to have
a 'no_proxy' environment variable set. For the aforementioned reasons the
issue was assessed as Low severity.

The vulnerable code was introduced in the following patch releases:
3.0.16, 3.1.8, 3.2.4, 3.3.3, 3.4.0 and 3.5.0.

The FIPS modules in 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this
issue, as the HTTP client implementation is outside the OpenSSL FIPS module
boundary.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2025-9232?


## How do I fix CVE-2025-9232?

Apply the vendor's patch.

## Is CVE-2025-9232 being exploited?

There is no known exploitation of CVE-2025-9232 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-9232 and fix it if it is affected.

What it is: CVE-2025-9232 is a medium-severity denial of service vulnerability in OpenSSL, published on 30 Sep 2025. 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-2025-9232 in the wild and no public exploit code.

Affected product: OpenSSL. 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-2025-9232/ (Markdown: https://insights.sbomify.com/CVE-2025-9232/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-9232
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-9232
- OSV: https://osv.dev/vulnerability/CVE-2025-9232

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-9232/
Summaries are generated and may contain mistakes; the official description above is the record.