CVE-2025-70956

CVE-2025-70956 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. 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-1321.

Key facts

Description

A State Pollution vulnerability was discovered in the TON Virtual Machine (TVM) before v2025.04. The issue exists in the RUNVM instruction logic (VmState::run_child_vm), which is responsible for initializing child virtual machines. The operation moves critical resources (specifically libraries and log) from the parent state to a new child state in a non-atomic manner. If an Out-of-Gas (OOG) exception occurs after resources are moved but before the state transition is finalized, the parent VM retains a corrupted state where these resources are emptied/invalid. Because RUNVM supports gas isolation, the parent VM continues execution with this corrupted state, leading to unexpected behavior or denial of service within the contract's context.

Frequently asked questions

What is CVE-2025-70956?
A State Pollution vulnerability was discovered in the TON Virtual Machine (TVM) before v2025.04. The issue exists in the RUNVM instruction logic (VmState::run_child_vm), which is responsible for initializing child virtual machines. The operation moves critical resources (specifically libraries and log) from the parent state to a new child state in a non-atomic manner. If an Out-of-Gas (OOG) exception occurs after resources are moved but before the state transition is finalized, the parent VM retains a corrupted state where these resources are emptied/invalid. Because RUNVM supports gas isolation, the parent VM continues execution with this corrupted state, leading to unexpected behavior or denial of service within the contract's context.
How severe is CVE-2025-70956?
CVE-2025-70956 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-70956 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-70956?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-70956 have an EU (EUVD) identifier?
Yes. CVE-2025-70956 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207530.
When was CVE-2025-70956 published?
CVE-2025-70956 was published on 2026-02-13 and last updated on 2026-06-17.

References

Other CWE-1321 (Prototype Pollution) vulnerabilities

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