Jackson Core: Document length constraint bypass in blocking, async, and DataInput parsers

Exploitation

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

CVSS

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Jackson Core 3.x does not consistently enforce StreamReadConstraints.maxDocumentLength. Oversized JSON documents can be accepted without a StreamConstraintsException in multiple parser entry points, which allows configured size limits to be bypassed and weakens denial-of-service protections. Details Three code paths where maxDocumentLength is not fully enforced: 1. Blocking parsers skip validation of the final in-memory buffer Blocking parsers validate only previously processed buffers, not the final in-memory buffer: - ReaderBasedJsonParser.java:255 - UTF8StreamJsonParser.java:208 Relevant code: This means the check occurs only when a completed buffer is rolled over. If an oversized document is fully contained in the final buffer, parsing can complete without any document-length exception. 2. Async parsers skip validation of the final chunk on end-of-input Async parsers validate previously processed chunks, but do not validate the final chunk on end-of-input: -…

Published by the source

4 Apr 2026, 04:17 UTC

Last modified by the source

8 Apr 2026, 22:42 UTC

Source last checked

26 Oct 2026, 16:45 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2m67-wjpj-xhg9

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# Patch Next advisory brief: GHSA-2m67-wjpj-xhg9

Advisory: Jackson Core: Document length constraint bypass in blocking, async, and DataInput parsers
IDs: GHSA-2m67-wjpj-xhg9
Record: https://patchnext.com/advisories/ghsa-2m67-wjpj-xhg9 (revision 1, source checked 26 Oct 2026, 16:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tools.jackson.core:jackson-core 3.1.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven tools.jackson.core:jackson-core: affected >= 3.0.0, <= 3.1.0; fixed in 3.1.1

## Suggested inspection (read-only)
- Maven tools.jackson.core:jackson-core: 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 tools.jackson.core:jackson-core.
- 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-2m67-wjpj-xhg9 (GitHub-reviewed advisory GHSA-2m67-wjpj-xhg9 lists affected ranges: Maven tools.jackson.core:jackson-core >=3.0.0 <=3.1.0)

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