CVE-2026-42796
Exploitation confirmed. First attested on 2026-09-18 by GCVE · previdian, GCVE · shadowserver.
- Published2026-05-04
- Fixed in2.39.10
- WeaknessCWE-306
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
Arelle before 2.39.10 contains an unauthenticated remote code execution vulnerability in the /rest/configure REST endpoint that accepts a plugins query parameter and forwards it to the plugin manager without authentication or authorization. Attackers can supply a URL to a malicious Python file through the plugins parameter, causing the Arelle webserver to download and execute the attacker-controlled code within the Arelle process with its privileges.
Timeline
dates in UTC- 2026-05-0418:16CVE publishedNVD
- 2026-09-18Listed as exploited by GCVEGCVE
- 2026-09-18Exploitation first reportedGCVE
- 2026-10-2319:23First public proof of conceptPoC-in-GitHub
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-42796?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-42796?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.39 | < 2.39.10 | 2.39.10 | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Workiva arelle to 2.39.10
Advisories and patches
- github.comPatch
- github.comRelease Notes
Detection
read 2026-10-23 19:25 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
Sources
- NVDCVE recordread 2026-10-23
- GCVEexploitation2026-09-18
- CISA-ADPSSVC decisionnone2026-05-04
- OpenCVESSVC decisionnone—
- CNACVSS 4.09.2read 2026-10-23
- CNACVSS 3.19.8read 2026-10-23
- CNAweakness (CWE)CWE-306read 2026-10-23
- FIRST EPSSEPSS score3.9 %2026-10-22
- PoC-in-GitHubproof of concept1read 2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CVSS 4.0 vector
- CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Published
- 2026-05-04
- Last Modified
- 2026-06-17
- NVD status
- Analyzed
Frequently asked questions
What is CVE-2026-42796?
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What is the CVSS score for CVE-2026-42796?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.