# CVE-2026-90819: A weakness has been identified in a2aproject a2a-java 1.2.0.


- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-wwww-x39f-grjc

## What is CVE-2026-90819?

CVE-2026-90819 is a medium-severity vulnerability in a2aproject a2a-java, published on 14 Sep 2026. 

### Official description

A weakness has been identified in a2aproject a2a-java 1.2.0. The affected element is the function BasePushNotificationSender.dispatchNotification of the file server-common/src/main/java/org/a2aproject/sdk/server/tasks/BasePushNotificationSender.java of the component Authorization Header Construction. This manipulation causes http response splitting. The attack can be initiated remotely. Upgrading to version 1.3.0 is sufficient to fix this issue. Patch name: 247a655043f145f6f8e3853724b6a543eaa02001. You should upgrade the affected component.

Weakness: CWE-93 (Improper Neutralization of CRLF Sequences), CWE-113 (Improper Neutralization of CRLF Sequences in HTTP Headers)

## Which versions are affected by CVE-2026-90819?


## How do I fix CVE-2026-90819?

No fix has been published for CVE-2026-90819 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90819 being exploited?

There is no known exploitation of CVE-2026-90819 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90819 and fix it if it is affected.

What it is: CVE-2026-90819 is a medium-severity vulnerability in a2aproject a2a-java, published on 14 Sep 2026. 
Exploitation: There is no known exploitation of CVE-2026-90819 in the wild and no public exploit code.

Affected product: a2aproject a2a-java. 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-2026-90819/ (Markdown: https://insights.sbomify.com/CVE-2026-90819/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90819
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90819
- OSV: https://osv.dev/vulnerability/CVE-2026-90819

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90819/
Summaries are generated and may contain mistakes; the official description above is the record.