VulnerabilityPublished 13 Feb 2026Updated 17 Feb 2026

CVE-2025-70956: TON Virtual Machine · Prototype Pollution

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2025-70956, developers and operators of the TON Virtual Machine should implement atomic state transitions when moving resources between parent and child VMs. This can be achieved by redesigning the RUNVM instruction logic to ensure that resource transfer and state finalization occur as a single atomic operation, preventing partial state corruption if an OOG exception occurs. Additionally, introducing robust exception handling and rollback mechanisms to restore the parent VM state upon failure during child VM initialization will prevent corrupted states from persisting. Monitoring and alerting for OOG exceptions during contract execution can help detect exploitation attempts or abnormal behavior early. Smart contract developers should also design contracts to minimize gas exhaustion risks and test for edge cases involving resource transfers. Until official patches are released, organizations should consider restricting or closely monitoring contract deployments that utilize RUNVM instructions. Participation in the TON developer community and applying updates promptly once patches become available is critical. Finally, conducting thorough code audits focusing on VM state management and resource handling will reduce the risk of similar vulnerabilities.

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.

Impact

The primary impact of CVE-2025-70956 is a denial of service condition within smart contracts running on the TON Virtual Machine. By corrupting the parent VM state during child VM initialization, the vulnerability can cause contracts to behave unpredictably or halt execution, disrupting blockchain operations dependent on these contracts. This can affect decentralized applications (dApps), financial transactions, and other services relying on TVM for execution integrity. Since the vulnerability does not affect confidentiality or integrity, data leakage or unauthorized modification is unlikely. However, the availability impact can undermine trust in the affected blockchain platform and cause financial or operational losses for organizations relying on uninterrupted smart contract execution. The ease of exploitation (no privileges or user interaction required) and remote attack vector increase the risk of automated attacks or exploitation attempts once the vulnerability becomes widely known. Organizations running nodes or developing smart contracts on TON must consider the risk of service disruption and potential cascading effects on dependent systems and users.

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (opens in a new tab)
Variant weakness
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
Implementation
By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
Architecture and Design
By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
Implementation · Input Validation
When handling untrusted objects, validating using a schema can be used.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Exploiting Incorrectly Configured Access Control Security Levels (opens in a new tab)
Manipulating User-Controlled Variables (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 20 Feb 2026, 22:37 UTC

WeaknessesCWE-1321

Technical details

References

Community reviews

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