CVE-2026-113602 json-smart CVE debrief

Who should care

Defenders responsible for json-smart deployments should assess exposure and verify affected versions. They should also consider upgrading to a version beyond 2.6.0 if possible to mitigate potential parser differentials with downstream parsers. Additionally, defenders should evaluate the potential for appending 0x1A and malformed content to pass JSONValue.parseStrict or isValidJsonStrict validation and take necessary precautions to prevent exploitation.

Why it matters

CVE-2026-113602 is a medium-severity vulnerability in json-smart that allows attackers to bypass strict-mode validation by inserting a 0x1A character. Defenders should verify affected versions, assess exposure, and consider upgrading to mitigate potential parser differentials with downstream parsers.

• Verify parser differentials with downstream parsers like Jackson or Gson
• Assess exposure in environments using json-smart through 2.6.0
• Evaluate potential for appending 0x1A and malformed content to pass JSONValue.parseStrict or isValidJsonStrict validation

Technical summary

json-smart through 2.6.0 contains an input validation bypass vulnerability that allows attackers to evade strict-mode trailing-data checks by inserting a literal 0x1A character. This vulnerability can create parser differentials with downstream parsers like Jackson or Gson, potentially leading to security issues if not addressed. Defenders should prioritize verifying affected versions and assessing exposure in their environments to mitigate potential impacts effectively and consider upgrading to a version beyond 2.6.0 if possible.

Defensive priority

Defenders should prioritize verifying affected versions and assessing exposure in their environments.

Recommended defensive actions

• Verify affected versions of json-smart in your environment
• Assess exposure to the vulnerability
• Consider upgrading to a version beyond 2.6.0 if possible
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, but limited information is available on exploitation or impact. Defenders should verify parser differentials with downstream parsers like Jackson or Gson, assess exposure in environments using json-smart through 2.6.0, and evaluate potential for appending 0x1A and malformed content to pass JSONValue.parseStrict or isValidJsonStrict validation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.