Cedar: JSON template is in scope missing slot-id validation allows link panic and decision divergence
GHSA-c33x-vcv4-vg3g
Cedar users must be using all of the following features to be affected by this advisory: JSON format policies, policy templates, and the is in scope condition. This advisory only affects JSON-formatted Cedar policy templates containing is in scope conditions that are malformed according to the Cedar syntax. It does not affect syntactically well-formed policies. Users of Cedar who author policies in the JSON format were able to write Cedar policies using the is in condition with an incorrect slot identifier in the principal and resource scope constraints (e.g., ?principal in the resource scope constraint) even though this is not allowed when parsing policies from the Cedar policy syntax. Internally, the slot identifiers were silently corrected (e.g. ?resource is placed in the resource scope constraint). If the policy contains exactly one slot in either the principal or resource position, then any attempt to create a linked policy from the template results in an error: the internal representation of the template does not contain the slot identifier as written in the malformed JSON policy (it has been corrected silently), so attempting to fill that slot is an error. If instead the…
Assessment
- CVSS
- 2.1 (v4.0)
- Severity
- Low
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 29 October 2026
- Last updated
- 29 October 2026
- Affected
- rust, npm · cedar-policy, @cedar-policy/cedar-wasm
- Weakness
- CWE-20
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:L/SC:L/SI:L/SA:L
At the source
References
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