How severe is CVE-2025-65570?

CVE-2025-65570 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-65570 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-65570?

CVE-2025-65570 affects Jsish. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-65570?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-65570 have an EU (EUVD) identifier?

Yes. CVE-2025-65570 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-205581.

When was CVE-2025-65570 published?

CVE-2025-65570 was published on 2025-12-29 and last updated on 2026-06-17.

CVE-2025-65570

CVE-2025-65570 is a critical-severity vulnerability in Jsish with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-843.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-205581
Weakness: CWE-843
Affected product: Jsish
Published: 2025-12-29
Last modified: 2026-06-17

Description

A type confusion in jsish 2.0 allows incorrect control flow during execution of the OP_NEXT opcode. When an “instanceof” expression uses an array element access as the left-hand operand inside a for-in loop, the instructions implementation leaves an additional array reference on the stack rather than consuming it during OP_INSTANCEOF. As a result, OP_NEXT interprets the array as an iterator object and reads the iterCmd function pointer from an invalid structure, potentially causing a crash or enabling code execution depending on heap layout.

Frequently asked questions

What is CVE-2025-65570?: A type confusion in jsish 2.0 allows incorrect control flow during execution of the OP_NEXT opcode. When an “instanceof” expression uses an array element access as the left-hand operand inside a for-in loop, the instructions implementation leaves an additional array reference on the stack rather than consuming it during OP_INSTANCEOF. As a result, OP_NEXT interprets the array as an iterator object and reads the iterCmd function pointer from an invalid structure, potentially causing a crash or enabling code execution depending on heap layout.
How severe is CVE-2025-65570?: CVE-2025-65570 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-65570 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-65570?: CVE-2025-65570 affects Jsish. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-65570?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-65570 have an EU (EUVD) identifier?: Yes. CVE-2025-65570 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-205581.
When was CVE-2025-65570 published?: CVE-2025-65570 was published on 2025-12-29 and last updated on 2026-06-17.

References

https://blog.mcsky.ro/writeups/2025/11/15/inline8-writeup.html

Affected products (1)

cpe:2.3:a:jsish:jsish:2.0:*:*:*:*:*:*:*

More vulnerabilities in Jsish

CVE-2024-24189 — Critical (CVSS 9.8): Jsish v3.5.0 (commit 42c694c) was discovered to contain a use-after-free via the SplitChar at ./src/jsiUtils.c.
CVE-2024-24188 — Critical (CVSS 9.8): Jsish v3.5.0 was discovered to contain a heap-buffer-overflow in ./src/jsiUtils.c.
CVE-2024-24186 — Critical (CVSS 9.8): Jsish v3.5.0 (commit 42c694c) was discovered to contain a stack-overflow via the component IterGetKeysCallback at…
CVE-2020-22875 — Critical (CVSS 9.8): Integer overflow vulnerability in function Jsi_ObjSetLength in jsish before 3.0.6, allows remote attackers to execute…
CVE-2020-22874 — Critical (CVSS 9.8): Integer overflow vulnerability in function Jsi_ObjArraySizer in jsish before 3.0.8, allows remote attackers to execute…
CVE-2020-22873 — Critical (CVSS 9.8): Buffer overflow vulnerability in function NumberToPrecisionCmd in jsish before 3.0.7, allows remote attackers to…

All CVEs affecting Jsish →

Other CWE-843 vulnerabilities

CVE-2021-33970 — Critical (CVSS 10.0): Buffer Overflow vulnerability in Qihoo 360 Chrome v13.0.2170.0 allows attacker to escalate priveleges.
CVE-2010-2299 — Critical (CVSS 10.0): The Clipboard::DispatchObject function in app/clipboard/clipboard.cc in Google Chrome before 5.0.375.70 does not…
CVE-2023-22579 — Critical (CVSS 9.9): Due to improper parameter filtering in the sequalize js library, can a attacker peform injection.
CVE-2026-104846 — Critical (CVSS 9.8): Seroval facilitates JS value stringification, including complex structures beyond JSON.stringify capabilities. From…
CVE-2026-71644 — Critical (CVSS 9.8): An issue in Robotics-STAR-Lab (SYSU STAR Group) RACER Tested affected version: commit abcdef1234567890 allows an…
CVE-2026-16919 — Critical (CVSS 9.8): IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to execute arbitrary code due to improper…

Browse all CWE-843 vulnerabilities →