CVE-2026-111658
SiteServer SSCMS through 7.4.0 contains an authorization bypass vulnerability in ChannelsController that allows site-scoped administrators to access other sites' channels by supplying foreign channel IDs.
Does this matter?
Lower severity and a low EPSS score (0.33%). Track it; it rarely justifies an emergency change on its own.
Description
SiteServer SSCMS through 7.4.0 contains an authorization bypass vulnerability in ChannelsController that allows site-scoped administrators to access other sites' channels by supplying foreign channel IDs. Attackers with Channels permission on one site can read and overwrite another site's channel names, file paths, templates, link URLs, and custom fields, breaking multi-site isolation.
- CVSS 4.0
- 5.1 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/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/M
- EPSS
- 0.33% probability · 25th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Source
- disclosure@vulncheck.com
EPSS moved from 0.3% on 17 October 2026 to 0.3% on 26 October 2026.
References
- https://github.com/siteserver/cms/blob/sscms-v7.2.1/src/SSCMS.Web/Controllers/Admin/Cms/Channels/ChannelsController.Get.cs#L16-L41
- https://github.com/siteserver/cms/blob/sscms-v7.2.1/src/SSCMS.Web/Controllers/Admin/Cms/Channels/ChannelsController.Update.cs#L14-L31
- https://hackmd.io/@hieuPenguinnn/sscms-cross-site-channel-idor
- https://www.vulncheck.com/advisories/siteserver-sscms-through-7.4.0-cross-site-authorization-bypass-via-channels-api
- https://hackmd.io/@hieuPenguinnn/sscms-cross-site-channel-idor
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.