CVE-2026-66393
CVE-2026-66393: 1 tracked advisory record across Red Hat. Compare vendor sources and published fix guidance.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
Vendor advisory comparison
Red Hat
1 advisory- Advisory severityHigh7.5
High [CVE-2026-66393] Denial of Service via unbounded recursion in JSONTaggedDecoder
CVE-2026-66393Source published Source updated
NLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decode_obj() that allows attackers to cause denial of service by supplying deeply nested JSON structures. Attackers can craft JSON payloads exceeding the recursion limit to trigger an unhandled RecursionError that crashes the Python process. A flaw was found in NLTK. This can cause the Python process to crash, leading to a denial of service. A denial of service flaw exists in NLTK's JSONTaggedDecoder, allowing remote attackers to crash Python processes by submitting crafted, deeply nested JSON data. This vulnerability poses a significant risk to Red Hat products that process untrusted JSON input using affected NLTK versions, as it can lead to service unavailability without requiring…
- Affected products in this advisory
- Red Hat Ansible Automation Platform 2
- Source-reported affected versions
- < 3.9.4
- Source-reported fixed versions
- No fixed-version detail extracted. This does not mean no fix exists.
- Mitigation guidance
- To mitigate this vulnerability, implement input validation to restrict the maximum nesting depth of JSON structures processed by NLTK. Ensure that any services or applications utilizing NLTK's JSONTaggedDecoder do not process untrusted or excessively nested JSON input without prior sanitization. If NLTK is not required to process external JSON, restrict its exposure to such data.
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