CVE-2024-38537
A public proof of concept exists; no exploitation attested.
- Published2024-07-02
- Fixed in2.39.1
- WeaknessCWE-829
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
Fides is an open-source privacy engineering platform. `fides.js`, a client-side script used to interact with the consent management features of Fides, used the `polyfill.io` domain in a very limited edge case, when it detected a legacy browser such as IE11 that did not support the fetch standard. Therefore it was possible for users of legacy, pre-2017 browsers who navigate to a page serving `fides.js` to download and execute malicious scripts from the `polyfill.io` domain when the domain was compromised and serving malware. No exploitation of `fides.js` via `polyfill.io` has been identified as of time of publication. The vulnerability has been patched in Fides version `2.39.1`. Users are advised to upgrade to this version or later to secure their systems against this threat. On Thursday, June 27, 2024, Cloudflare and Namecheap intervened at a domain level to ensure `polyfill.io` and its subdomains could not resolve to the compromised service, rendering this vulnerability unexploitable. Prior to the domain level intervention, there were no server-side workarounds and the confidentiality, integrity, and availability impacts of this vulnerability were high. Clients could ensure they were not affected by using a modern browser that supported the fetch standard.
Timeline
dates in UTC- 2024-07-0220:15CVE publishedNVD
- 2026-10-2319:23First public proof of conceptPoC-in-GitHub
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2024-38537?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2024-38537?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.39 | < 2.39.1 | 2.39.1 | NVD · OSV |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Ethyca fides to 2.39.1
Advisories and patches
- github.comPatch
- github.comPatch
- github.comPatch
Detection
read 2026-10-23 19:24 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- 1 repository, unverifiedHavoc10-sw/Detect_polyfill_CVE-2024-38537- PoC-in-GitHub
Sources
- CISA-ADPSSVC decisionnone2024-07-02
- OpenCVESSVC decisionnone—
- CNACVSS 3.10read 2026-10-23
- NVDCVSS 3.19.8read 2026-10-23
- CNAweakness (CWE)CWE-829read 2026-10-23
- FIRST EPSSEPSS score1.4 %2026-10-23
- PoC-in-GitHubproof of concept1read 2026-10-23
- OSVaffected packages—
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2024-07-02
- Last Modified
- 2026-06-17
- NVD status
- Analyzed
Frequently asked questions
What is CVE-2024-38537?
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What is the CVSS score for CVE-2024-38537?
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