core: Improper Cleanup on Thrown Exception
CVE-2026-40583 is a high-severity improper cleanup on thrown exception vulnerability in core from UltraDAGcom, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected core versions: = 0.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.38% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of core you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| UltraDAGcom | core | = 0.1 | Not stated |
| Ultradag | Ultradag | 0.1.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- LowLimited modification of data is possible.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.8 | High | CNA (github.com) |
| CVSS 3.1 | 8.2 | High | NVD |
Official description
UltraDAG is a minimal DAG-BFT blockchain in Rust. In version 0.1, a non-council attacker can submit a signed SmartOp::Vote transaction that passes signature, nonce, and balance prechecks, but fails authorization only after state mutation has already occurred.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Cleanup on Thrown Exception
The product does not clean up its state or incorrectly cleans up its state when an exception is thrown.
How developers prevent this class of flaw
- If one breaks from a loop or function by throwing an exception, make sure that cleanup happens or that you should exit the program. Use throwing exceptions sparsely.
More Improper Cleanup on Thrown Exception vulnerabilities (CWE-460)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/UltraDAGcom/core/security/advisories/GHSA-q8wx-2crx-c7ppExploit, Mitigation
Patches and release notes
Other vulnerabilities in core
- 8.8 High severity
Recent Improper Cleanup on Thrown Exception vulnerabilities
- 7.5 High severity
- 7.4 High severity
- 7.5 High severity
- 7.5 High severity
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