CVE-2025-52999 is a high-severity stack-based buffer overflow vulnerability (CWE-121) found in the jackson-core library, a core component of the FasterXML Jackson Data Processor widely used for JSON parsing and generation in Java applications. Versions of jackson-core prior to 2.15.0 are affected. The vulnerability arises when parsing input files containing deeply nested JSON data structures. Without proper limits, the recursive parsing can cause a StackOverflowError due to excessive call stack usage. This can lead to application crashes or potentially exploitable conditions if an attacker crafts maliciously nested JSON inputs. The vulnerability affects not only jackson-core but also jackson-databind, which depends on jackson-core for JSON parsing. In version 2.15.0, a configurable depth limit (defaulting to 1000 levels) was introduced to prevent excessive recursion. When this limit is exceeded, jackson-core throws a StreamConstraintsException instead of crashing. No known exploits are currently reported in the wild. The CVSS 4.0 base score is 8.7 (high), reflecting that the vulnerability is remotely exploitable without authentication or user interaction, with a high impact on availability due to potential denial-of-service via application crashes. Confidentiality and integrity impacts are not indicated. The vulnerability is exploitable over the network by sending crafted JSON payloads to affected applications that use vulnerable jackson-core versions for parsing untrusted input. This makes it a significant risk for server-side applications, APIs, and microservices processing external JSON data. The lack of authentication or user interaction requirements increases the attack surface. The absence of a patch link suggests that users should upgrade to jackson-core 2.15.0 or later to mitigate the issue. As a temporary workaround, users should avoid parsing JSON inputs from untrusted sources or implement input validation to limit nesting depth before parsing.

For European organizations, this vulnerability poses a substantial risk, especially for those relying on Java-based web services, APIs, or microservices that utilize jackson-core for JSON processing. Exploitation can lead to denial-of-service conditions by crashing critical applications, resulting in service outages, degraded user experience, and potential operational disruptions. Industries such as finance, healthcare, telecommunications, and government services, which often process large volumes of JSON data and require high availability, may be particularly affected. The vulnerability does not directly compromise data confidentiality or integrity but can indirectly impact business continuity and trust. Additionally, organizations exposed to internet-facing services accepting JSON input from external or untrusted sources are at higher risk. Given the widespread adoption of jackson-core in enterprise Java applications across Europe, the scope of affected systems is broad. The ease of exploitation without authentication or user interaction further elevates the threat level. While no active exploits are reported, the vulnerability's characteristics make it a likely target for attackers seeking denial-of-service vectors or as a stepping stone for more complex attacks.

1. Immediate upgrade: Organizations should prioritize upgrading jackson-core to version 2.15.0 or later, which includes the configurable depth limit to prevent stack overflow. 2. Input validation: Implement strict validation on JSON inputs to limit nesting depth and reject excessively nested or malformed JSON before parsing. 3. Use of JSON schema validation: Employ JSON schema validation tools to enforce structural constraints on incoming data. 4. Runtime monitoring: Deploy application performance and error monitoring to detect unusual stack overflow errors or crashes related to JSON parsing. 5. Network filtering: Restrict access to JSON-processing endpoints to trusted clients where possible, reducing exposure to crafted malicious inputs. 6. Dependency management: Regularly audit and update all dependencies, including jackson-databind, to ensure they incorporate the patched jackson-core version. 7. Defensive coding: Where feasible, implement try-catch blocks around JSON parsing to gracefully handle exceptions like StreamConstraintsException and prevent application crashes. 8. Security testing: Incorporate fuzz testing and penetration testing focused on JSON input handling to identify and remediate similar vulnerabilities proactively.