core-moos: Signed to Unsigned Conversion Error
CVE-2026-85441 is a high-severity signed to unsigned conversion error vulnerability in core-moos from Themoos, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected core-moos versions: 10.4.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of core-moos 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
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.5 | High | CNA (vulncheck.com) |
Official description
MOOS core-moos through 10.4.0 fails to validate that serialized string lengths are non-negative in CMOOSMsg::operator>>. Unauthenticated attackers can send a crafted message with a negative length value to the MOOSDB port, causing an unhandled exception that terminates the database process.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Signed to Unsigned Conversion Error
The product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive.
More Signed to Unsigned Conversion Error vulnerabilities (CWE-195)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- github.com/themoos/core-moos/pull/74Issue Tracking
Third-party and government advisories
Other references
- github.com/themoos/core-moosProduct
Other vulnerabilities in core-moos
- 8.2 High severity
- 7.1 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
Recent Signed to Unsigned Conversion Error vulnerabilities
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
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