Full Report
Heap-based Buffer Overflow vulnerability (CVE-2026-8484) has been found in jansi library.
Analysis Summary
# Vulnerability: Heap-based Buffer Overflow in jansi Library
## CVE Details
- **CVE ID**: CVE-2026-8484
- **CVSS Score**: Pending/Not specified in source (High based on CWE-122 characteristics)
- **CWE**: CWE-122 (Heap-based Buffer Overflow)
## Affected Systems
- **Products**: FuseSource jansi (Java library for generating ANSI escape sequences)
- **Versions**: All versions through 2.4.3
- **Configurations**: Applications utilizing jansi’s JNI (Java Native Interface) functionality, specifically the `ioctl()` wrapper.
## Vulnerability Description
A heap-based buffer overflow exists within the jansi library’s JNI implementation of the `ioctl()` wrapper. The flaw stems from a lack of size verification for the argument array before passing it to the underlying system call. When an application passes an unexpectedly sized or malicious array to this wrapper, it can result in memory corruption within the heap.
## Exploitation
- **Status**: Reported/Disclosed (No evidence of active exploitation in the wild mentioned)
- **Complexity**: Low to Medium
- **Attack Vector**: Local (Typically requires the ability to pass arguments to the library's JNI methods)
## Impact
- **Confidentiality**: None/Low (Potential for memory leakage depending on exploit)
- **Integrity**: Medium (Heap corruption can alter application state)
- **Availability**: High (Primary impact is application crashes and Denial of Service (DoS))
## Remediation
### Patches
- **No Path Available**: As of the publication date (June 16, 2026), the FuseSource jansi project is considered **unmaintained**. No official security patches have been released.
### Workarounds
- **Library Replacement**: Migrating to a maintained alternative library for ANSI escape sequence handling.
- **Input Validation**: Implementing strict application-level validation to ensure that any data passed to jansi's `ioctl()` wrappers conforms to expected size limits.
- **Access Control**: Restricting the ability of untrusted users or processes to interact with components that utilize the jansi JNI layer.
## Detection
- **Indicators of Compromise**: Unexpected application crashes (SIGSEGV/Segmentation Faults) originating from the jansi native library component.
- **Detection Methods**:
- Scanning project dependencies (Software Bill of Materials - SBOM) for `fusesource:jansi` versions ≤ 2.4.3.
- Using static analysis (SAST) to identify calls to the `ioctl()` wrapper within the jansi library.
## References
- **Vendor Advisory**: hxxps[://]www[.]cve[.]org/CVERecord?id=CVE-2026-8484
- **CERT Polska Advisory**: hxxps[://]cert[.]pl/en/posts/2026/06/vulnerability-in-jansi-library/ (Refers to coordinated disclosure)
- **CWE-122 Details**: hxxps[://]cwe[.]mitre[.]org/data/definitions/122[.]html