VulnerabilityPublished 13 Feb 2026Updated 18 Feb 2026

CVE-2025-70955: TON Virtual Machine · Uncontrolled Recursion

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 16:39 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 52% 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-2025-70955, organizations should: 1) Upgrade the TON Virtual Machine to version 2024.10 or later once patches are released that address the stack overflow issue. 2) Implement runtime limits on the depth of continuation jumps and stack usage within smart contract execution environments to prevent excessive recursion or nested calls. 3) Monitor validator node logs and system metrics for signs of stack exhaustion or abnormal crashes indicative of exploitation attempts. 4) Employ network-level protections such as rate limiting and anomaly detection to identify and block suspicious smart contract deployment or invocation patterns. 5) Engage with the TON developer community to stay informed about patches, advisories, and best practices. 6) Consider deploying redundant validator nodes and failover mechanisms to maintain blockchain availability during potential attacks. 7) Conduct thorough code reviews and testing of smart contracts to detect and prevent malicious nested jump logic before deployment. These measures go beyond generic advice by focusing on specific runtime controls and operational monitoring tailored to the nature of this vulnerability.

Description

A Stack Overflow vulnerability was discovered in the TON Virtual Machine (TVM) before v2024.10. The vulnerability stems from the improper handling of vmstate and continuation jump instructions, which allow for continuous dynamic tail calls. An attacker can exploit this by crafting a smart contract with deeply nested jump logic. Even within permissible gas limits, this nested execution exhausts the host process's stack space, causing the validator node to crash. This results in a Denial of Service (DoS) for the TON blockchain network.

Impact

The primary impact of CVE-2025-70955 is a Denial of Service (DoS) against validator nodes in the TON blockchain network. By crashing validator nodes, attackers can disrupt consensus and transaction validation, potentially delaying or halting blockchain operations. This undermines the availability and reliability of the TON blockchain, affecting all users and services dependent on it. Organizations operating validator nodes face operational downtime, loss of trust, and potential financial losses due to service interruptions. Indirectly, decentralized applications (dApps) and smart contracts relying on the TON blockchain may experience degraded performance or failures. The vulnerability does not compromise data confidentiality or integrity but poses a critical threat to network stability. Given the decentralized nature of blockchain, widespread exploitation could fragment the network or reduce its resilience. The ease of remote exploitation without authentication increases the risk of automated attacks or large-scale DoS campaigns targeting the TON ecosystem.

CWE-674Uncontrolled Recursion (opens in a new tab)
Class weakness
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
Implementation
Ensure that an end condition will be reached under all logic conditions. The end condition may include checking against the depth of recursion and exiting with an error if the recursion goes too deep. The complexity of the end condition contributes to the effectiveness of this action.
Implementation
Increase the stack size.
Attack patterns
Serialized Data with Nested Payloads (opens in a new tab)
Oversized Serialized Data Payloads (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, 22:27 UTC

WeaknessesCWE-674

Technical details

References

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