# CVE-2026-107231: AsyncHttpClient: Digest challenge without a usable nonce downgrades to Basic and sends the password in cleartext

> A malicious server or proxy can force the AsyncHttpClient library to downgrade Digest authentication to Basic, exposing user credentials in cleartext.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/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:** 7 Oct 2026
- **Updated:** 10 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-107231, ECHO-32cd-c594-6bfe, GHSA-rqf5-2wxv-rjf4, MINI-cmq8-5hpf-jc57, MINI-mcwr-r6q6-7hcq, MINI-qrr3-j75j-6g4f, MINI-wpfq-xc34-fh8r, ROOT-APP-MAVEN-CVE-2026-107231, UBUNTU-CVE-2026-107231

## What is CVE-2026-107231?

CVE-2026-107231 is a high-severity vulnerability in AsyncHttpClient async-http-client, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. Prior to 3.0.13 and 2.16.1, Realm.Builder treats a Digest challenge that yields no usable nonce as a Basic challenge. A malicious origin or proxy can label a challenge Digest while omitting or emptying the nonce, causing the client to resend the username and password using reversible Basic authentication. Both origin and proxy challenge parsers are affected. This issue is fixed in versions 3.0.13 and 2.16.1.

Weakness: CWE-757 (Selection of Less-Secure Algorithm During Negotiation), CWE-522 (Insufficiently Protected Credentials), CWE-319 (Cleartext Transmission of Sensitive Information)

## Which versions are affected by CVE-2026-107231?

4 open source packages ship an affected version, including org.asynchttpclient:async-http-client.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.asynchttpclient:async-http-client` | Maven | From 2.0.0 | 2.16.1 |
| `org.asynchttpclient:async-http-client` | Maven | From 2.0.0 | 2.16.1 |
| `org.asynchttpclient:async-http-client` | Maven | From 3.0.0.Beta1 | 3.0.13 |
| `org.asynchttpclient:async-http-client` | Maven | From 3.0.0.Beta1 | 3.0.13 |

## How do I fix CVE-2026-107231?

Upgrade org.asynchttpclient:async-http-client to a fixed version for your release line: 2.16.1 or 3.0.13.

## Is CVE-2026-107231 being exploited?

There is no known exploitation of CVE-2026-107231 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107231 and fix it if it is affected.

What it is: CVE-2026-107231 is a high-severity vulnerability in AsyncHttpClient async-http-client, published on 7 Oct 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-2026-107231 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.asynchttpclient:async-http-client (Maven): affected from 2.0.0; fixed in 2.16.1
- org.asynchttpclient:async-http-client (Maven): affected from 2.0.0; fixed in 2.16.1
- org.asynchttpclient:async-http-client (Maven): affected from 3.0.0.Beta1; fixed in 3.0.13
- org.asynchttpclient:async-http-client (Maven): affected from 3.0.0.Beta1; fixed in 3.0.13

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-2026-107231/ (Markdown: https://insights.sbomify.com/CVE-2026-107231/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107231
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107231
- OSV: https://osv.dev/vulnerability/CVE-2026-107231

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107231/
Summaries are generated and may contain mistakes; the official description above is the record.