CVE-2026-29062 — jackson-core
Fix: FasterXML/jackson-core@8b25fd6CVE-2026-29062 is a CWE-770 vulnerability in tools.jackson.core:jackson-core. A fix is available for tools.jackson.core:jackson-core — see the affected versions and patch details below.
jackson-core: Nesting Depth Constraint Bypass in `UTF8DataInputJsonParser` potentially allowing Resource Exhaustion
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-29062.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
tools.jackson.core:jackson-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The UTF8DataInputJsonParser, which is used when parsing from a java.io.DataInput source, bypasses the maxNestingDepth constraint (default: 500) defined in StreamReadConstraints.
A similar issue was found in ReaderBasedJsonParser.
This allows a user to supply a JSON document with excessive nesting, which can cause a StackOverflowError when the structure is processed, leading to a Denial of Service (DoS).
The related fix for com.fasterxml.jackson.core:jackson-core, CVE-2025-52999, was not fully applied to tools.jackson.core:jackson-core until the 3.1.0 release. It is recommended that 3.0.x users upgrade.
Patches
jackson-core contains a configurable limit for how deep Jackson will traverse in an input document. This check was missing in a few places in tools.jackson.core:jackson-core.
The change is in https://github.com/FasterXML/jackson-core/pull/1554. jackson-core will throw a StreamConstraintsException if the limit is reached.
jackson-databind also benefits from this change because it uses jackson-core to parse JSON inputs.
Workarounds
Users should avoid parsing input files from untrusted sources.
Resources
GHSA-6v53-7c9g-w56r https://nvd.nist.gov/vuln/detail/CVE-2025-52999 https://github.com/FasterXML/jackson-core/pull/1554
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | tools.jackson.core:jackson-core | ≥ 3.0.0&&< 3.1.0 | 3.1.0tools.jackson.core:jackson-core:3.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tools.jackson.core:jackson-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tools.jackson.core:jackson-core to 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29062 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-29062 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-29062. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-29062 in your dependencies?
O3 Security finds CVE-2026-29062 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.