Micronaut's HTTP client is vulnerable to HTTP Request Header Injection

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2020-7611: 1.81% estimated exploitation activity in the next 30 days; percentile 78.69 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Vulnerability Micronaut's HTTP client is vulnerable to "HTTP Request Header Injection" due to not validating request headers passed to the client. Example of vulnerable code: In the above case a query value received from a user is passed as a header value to the client. Since the client doesn't validate the header value the request headers and body have the potential to be manipulated. For example, a user that supplies the following payload, can force the client to make multiple attacker-controlled HTTP requests. Note that using @HeaderValue instead of @QueryValue is not vulnerable since Micronaut's HTTP server does validate the headers passed to the server, so the exploit can only be triggered by using user data that is not an HTTP header (query values, form data etc.). Impact The attacker is able to control the entirety of the HTTP body for their custom requests. As such, this vulnerability enables attackers to perform a variant of Server Side Request Forgery. Patches The problem…

Published by the source

30 Mar 2020, 20:54 UTC

Last modified by the source

6 Nov 2023, 11:08 UTC

Source last checked

26 Oct 2026, 16:16 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-694p-xrhg-x3wm

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# Patch Next advisory brief: CVE-2020-7611

Advisory: Micronaut's HTTP client is vulnerable to HTTP Request Header Injection
IDs: CVE-2020-7611, GHSA-694p-xrhg-x3wm
Record: https://patchnext.com/advisories/cve-2020-7611 (revision 1, source checked 26 Oct 2026, 16:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: io.micronaut:micronaut-http-client 1.3.2, 1.2.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven io.micronaut:micronaut-http-client: affected < 1.2.11; >= 1.3.0, < 1.3.2; fixed in 1.2.11, 1.3.2

## Suggested inspection (read-only)
- Maven io.micronaut:micronaut-http-client: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on io.micronaut:micronaut-http-client.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-694p-xrhg-x3wm (GitHub-reviewed advisory GHSA-694p-xrhg-x3wm lists affected ranges: Maven io.micronaut:micronaut-http-client >=0 =1.3.0 <1.3.2)

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