CVE-2026-33320: CVE-2026-33320: Dasel is a command-line tool and library for querying, modifying, and transforming data st…
tomwright · dasel · NVD published 2026-03-24 · posted 2026-05-04 · last modified 2026-06-17
What it is
Dasel is a command-line tool and library for querying, modifying, and transforming data structures. Starting in version 3.0.0 and prior to version 3.3.1, Dasel's YAML reader allows an attacker who can supply YAML for processing to trigger extreme CPU and memory consumption. The issue is in the library's own `UnmarshalYAML` implementation, which manually resolves alias nodes by recursively following `yaml.Node.Alias` pointers without any expansion budget, bypassing go-yaml v4's built-in alias expansion limit. Version 3.3.2 contains a patch for the issue.
| Weakness | CWE-674 |
|---|---|
| CVSS vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (source: [email protected]) |
| ATT&CK tactics | n/a |
Exploitation evidence
First exploit evidence seen: 2026-05-04 (earliest date across the sources below).
Exploited in the wild
No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).
Public exploit code
GitHub proof-of-concept repositories
3 public repositories from 3 accounts, first seen 2026-05-04. Most starred: nedlir/dasel-hardened-container (0 stars), view repository.
Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.
Sources: nomi-sec/PoC-in-GitHub.
How to fix it
Fixed versions
- tomwright dasel: upgrade to 3.3.2 or later (affected from 3.0.0)
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://github.com/TomWright/dasel/security/advisories/GHSA-4fcp-jxh7-23x8 (Exploit, Mitigation, Vendor Advisory)
Detection Generic guidance
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.