CVE-2026-50193 - jackson-databind deeply nested JsonNode denial of service

CVE-2026-50193 + jackson-databind deeply nested JsonNode denial of service + High + 2026-06-23

One-sentence business risk

Small deeply nested JSON bodies can burn application threads and create customer-visible outages.

Research notes

  • Root cause: jackson-databind 2.13.x can consume excessive resources when a service reads deeply nested JSON into JsonNode with readTree() and serializes it back with JsonNode.toString().
  • Affected versions: jackson-databind 2.13.0 through before 2.14.0 when readTree() output is serialized with JsonNode.toString().
  • Fixed / safe versions: jackson-databind 2.14.0 or later.
  • Public exploit / PoC signal: public PoC or exploit details are referenced by NVD; use only safe regression tests and do not execute exploit payloads against production.
  • CVSS: 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Exact vulnerable code pattern

JsonNode node = mapper.readTree(requestBody);
logger.info("payload={}", node.toString());

Fixed / mitigated code pattern

JsonFactory factory = JsonFactory.builder()
    .streamReadConstraints(StreamReadConstraints.builder().maxNestingDepth(200).build())
    .build();
ObjectMapper mapper = new ObjectMapper(factory);
JsonNode node = mapper.readTree(limitedBody);
String safeJson = mapper.writeValueAsString(node);

Dependency or runtime update:

mvn -q dependency:tree | grep -i jackson-databind
# set jackson-databind to 2.14.0+ in Maven/Gradle
mvn test

Step-by-step integration guide

  1. Inventory com.fasterxml.jackson.core:jackson-databind in source, lockfiles, SBOMs, CI images, containers, deployment manifests, and managed runtimes.
  2. Upgrade or patch to jackson-databind 2.14.0 or later; if no upstream package is available, apply the local guard shown above and track the vendor release as a blocking follow-up.
  3. Replace every vulnerable dos pattern with a fail-closed implementation that validates ownership, bounds, canonical paths, origin/session binding, or parser limits before acting.
  4. Add a regression test that reproduces the advisory shape safely and proves the request is rejected, bounded, or authorized.
  5. Deploy through canary, monitor auth, file, parser, crash, and CI-runner logs, then remove temporary edge blocks only after all runtimes are fixed.

Alternative mitigations

  • Disable the vulnerable feature path, decoder, plugin, runner backend, proxy agent, or route while the patch rolls out.
  • Add WAF/reverse-proxy rules for SQL metacharacters, traversal tokens, unsafe Docker flags, oversized/nested payloads, or unexpected session-origin transitions matching this trigger class.
  • Restrict egress and access to untrusted artifacts, SSH servers, media uploads, workflow execution, and administrative delegation until fixed versions are verified.
  • Rotate credentials and invalidate sessions if logs show the vulnerable path was reachable by untrusted users.

Detection signature

id: cve-2026-50193-jackson-databind-deeply-nested-jsonnode-denial-o
source: NVD
package_or_product: "com.fasterxml.jackson.core:jackson-databind"
affected: "jackson-databind 2.13.0 through before 2.14.0 when readTree() output is serialized with JsonNode.toString()"
fixed: "jackson-databind 2.14.0 or later"
cvss: "7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
signals:
  - "dos"
  - "CVE-2026-50193"
  - "com.fasterxml.jackson.core:jackson-databind"
action: "upgrade, add a regression test, and verify deploy artifact"

Copy-paste skill

You are remediating CVE-2026-50193 (jackson-databind deeply nested JsonNode denial of service) in this repository.

Produce a reviewer-ready PR or TRIAGE.md. Inventory com.fasterxml.jackson.core:jackson-databind across source, lockfiles, images, CI, deployment manifests, and SBOMs. Apply jackson-databind 2.14.0 or later. Replace the vulnerable dos pattern with the fail-closed pattern, add a regression test for the advisory trigger, and document owner, rollout, rollback, and validation evidence. Do not run public exploit PoCs against production or expose secrets in logs.

Keywords, affected tech stack, and revenue tags

  • Keywords: CVE-2026-50193, dos, com.fasterxml.jackson.core:jackson-databind, NVD.
  • Affected tech stack: java/maven.
  • Revenue tags: sellable_to_fintech, enterprise_blocker, high_priority_sla.

References