---
title: "CVE-2026-90819: a2aproject a2a-java - HTTP Response Splitting"
description: "a2aproject a2a-java 1.2.0 contains an HTTP response splitting vulnerability caused by improper Authorization Header Construction in BasePushNotificationSender.dispatchNotification, letting remote attackers manipulate HTTP responses, exploit requires crafted requests."
url: https://panop.io/threat-heartbeat/CVE-2026-90819/
---

# CVE-2026-90819 a2aproject a2a-java - HTTP Response Splitting

a2aproject a2a-java 1.2.0 contains an HTTP response splitting vulnerability caused by improper Authorization Header Construction in BasePushNotificationSender.dispatchNotification, letting remote attackers manipulate HTTP responses, exploit requires crafted requests.

CVSS base score 7.3 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.66% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-90819)

## Details

Type

HTTP Response Splitting

Impact

HTTP Request Smuggling

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Published

14 September 2026

Updated

15 October 2026

Weakness

[CWE-93](https://cwe.mitre.org/data/definitions/93.html)

## Vendor fix

Upgrade to version 1.3.0.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-90819](https://nvd.nist.gov/vuln/detail/CVE-2026-90819)
- [https://github.com/a2aproject/a2a-java/](https://github.com/a2aproject/a2a-java/)
- [https://github.com/a2aproject/a2a-java/commit/247a655043f145f6f8e3853724b6a543eaa02001](https://github.com/a2aproject/a2a-java/commit/247a655043f145f6f8e3853724b6a543eaa02001)
- [https://github.com/a2aproject/a2a-java/pull/1043](https://github.com/a2aproject/a2a-java/pull/1043)
- [https://github.com/a2aproject/a2a-java/pull/1053](https://github.com/a2aproject/a2a-java/pull/1053)
- [https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final](https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final)
- [https://vuldb.com/cve/CVE-2026-90819](https://vuldb.com/cve/CVE-2026-90819)
- [https://vuldb.com/submit/922996](https://vuldb.com/submit/922996)
- [https://vuldb.com/vuln/403322/cti](https://vuldb.com/vuln/403322/cti)
- [https://vuldb.com/vuln/403322](https://vuldb.com/vuln/403322)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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