CVE-2023-49105
CriticalExploitedPublic exploitAn attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured.
Published Nov 21, 2023 · Updated Oct 8, 2026
Key Facts
Patch immediately- CVE-2023-49105 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Owncloud Server.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 26, 2026. Public exploit code is available.
- EPSS estimates a 43% probability of exploitation in the next 30 days.
- Fixed versions are available, including Owncloud Server 10.13.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
43%
Higher than 98.7% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2023-49105 brief as a PDF
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Description
An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Aug 27, 2026 | Aug 30, 2026 | Not reported |
| Industry KEV feed | Aug 26, 2026 | Aug 30, 2026 | Not reported |
| CIRCL KEV | Aug 27, 2026 | Aug 30, 2026 | Not reported |
| ENISA EUVD | Aug 27, 2026 | n/a | Not reported |
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Owncloud ServerOwncloud | See advisory | 10.13.1 |
Patched Releases
Owncloud Server
10.13.1
Timeline
Publicly disclosed
Nov 21, 2023
Added to Industry KEV feed
Aug 26, 2026
Added to CISA KEV
Aug 27, 2026
Added to CIRCL KEV
Aug 27, 2026
Added to ENISA EUVD
Aug 27, 2026
Last updated
Oct 8, 2026
Weakness Type
- CWE-287 Improper Authentication
References
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2023/49xxx/CVE-2023-49105.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2023-49105
- advisoryhttps://owncloud.com/security-advisories/webdav-api-authentication-bypass-using-pre-signed-urls/
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
An issue was discovered in ownCloud owncloud/core before 10.13.1.
Affected: Owncloud Server. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Aug 26, 2026.
Yes. It was added on Aug 27, 2026 with a federal remediation due date of Aug 30, 2026.
Public exploit code is available.
Fixed versions are available, including Owncloud Server 10.13.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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