cFS: Deserialization of Untrusted Data
CVE-2026-5473 is a high-severity deserialization of untrusted data vulnerability in cFS from Nasa, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected cFS versions: 7.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.23% 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 cFS you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| NASA | cFS | 7.0 | Not stated |
| Nasa | Core Flight System | 7.0.0 and earlier | 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 1.1 | Low | CNA (vuldb.com) |
| CVSS 3.1 | 4.5 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.0 | High | NVD |
| CVSS 2.0 | 3.5 | Low | CNA (vuldb.com) |
Official description
A vulnerability has been found in NASA cFS up to 7.0.0. The impacted element is the function pickle.load of the component Pickle Module. Such manipulation leads to deserialization. The attack needs to be performed locally. The attack requires a high level of complexity. The exploitability is regarded as difficult. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/submit/781949Third Party Advisory, VDB Entry
- vuldb.com/vuln/355077Third Party Advisory, VDB Entry
Other references
- github.com/nasa/cFS/Product
- github.com/nasa/cFS/issues/951Issue Tracking
- vuldb.com/vuln/355077/ctiPermissions Required, VDB Entry
Other vulnerabilities in cFS
- 7.4 High severity
- 8.8 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 7.5 High severity
- 9.9 Critical severity
- 7.2 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
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