Access of Resource Using Incompatible Type ('Type Confusion') Affecting pcmacdon/jsish package, versions [0,)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-PCMACDONJSISH-14742502
- published31 Dec 2025
- disclosed29 Dec 2025
- creditMcsky23
Introduced: 29 Dec 2025
CVE-2025-65570 (opens in a new tab)How to fix?
There is no fixed version for pcmacdon/jsish.
Overview
Affected versions of this package are vulnerable to Access of Resource Using Incompatible Type ('Type Confusion') via the execution of the OP_NEXT opcode when an instanceof expression uses array element access as the left-hand operand inside a for-in loop. An attacker can cause a crash or execute arbitrary code by manipulating the stack to leave an additional array reference, which is then misinterpreted as an iterator object, leading to the reading of a function pointer from an invalid structure.