CVE-2023-6245Infinite decoding loop through specially crafted payload
- 7.5HighCVSS base score
- 1.2%Exploitation in 30 daysEPSS · top 31% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
The Candid library causes a Denial of Service while parsing a specially crafted payload with 'empty' data type. For example, if the payload is `record { * ; empty }` and the canister interface expects `record { * }` then the Rust candid decoder treats empty as an extra field required by the type. The problem with the type empty is that the candid Rust library wrongly categorizes empty as a recoverable error when skipping the field and thus causing an infinite decoding loop. Canisters using affected versions of candid are exposed to denial of service by causing the decoding to run indefinitely until the canister traps due to reaching maximum instruction limit per execution round. Repeated exposure to the payload will result in degraded performance of the canister. Note: Canisters written in Motoko are unaffected.
Timeline
ID reserved
By Dfinity
- 17 days later
· 17 days later
Published
- 12 months later
· 12 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| DfinityCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.2% · top 31% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected 0.9.0 – < 0.9.10
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- crates.iocandidGHSA-7787-p7x6-fq3j (opens in a new tab)
References
References5
- https://github.com/dfinity/candid/pull/478 (opens in a new tab)x_transferred
- https://internetcomputer.org/docs/current/references/candid-ref (opens in a new tab)x_transferred
- https://github.com/dfinity/candid/blob/master/spec/Candid.md (opens in a new tab)x_transferred
- https://github.com/dfinity/candid/security/advisories/GHSA-7787-p7x6-fq3j (opens in a new tab)x_transferred
- https://internetcomputer.org/docs/current/references/ic-interface-spec (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2023-3140 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-7787-p7x6-fq3j (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2023-6245)Record last updated .