CVE-2026-103397
OpenSave before 2.4.0-beta.1 fails to validate sender identity in WAN relay requests, allowing unpaired room members to impersonate paired devices by spoofing the RelayMessage From field.
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
Description
OpenSave before 2.4.0-beta.1 fails to validate sender identity in WAN relay requests, allowing unpaired room members to impersonate paired devices by spoofing the RelayMessage From field. Attackers who know the room code can join, read paired peer identifiers from announcements, and send forged requests to access protected sync routes including save data, snapshots, and file operations.
- CVSS 4.0
- 6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/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
- 0.22% probability · 12th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-290
- Source
- disclosure@vulncheck.com
EPSS moved from 0.4% on 1 October 2026 to 0.2% on 26 October 2026.
References
- https://gist.github.com/mansurmavlankulov/2ca66f95965fb9d4aab353bcf2434cdb
- https://github.com/Liquid-co/OpenSave
- https://github.com/Liquid-co/OpenSave/blob/v2.3.1/internal/p2p/wanclient_handlers.go#L268-L282
- https://github.com/Liquid-co/OpenSave/commit/2f2612b13233ac123e01a03cb3008c44bacaeae3
- https://www.vulncheck.com/advisories/opensave-before-2.4.0-beta.1-authentication-bypass-via-spoofed-relay-sender
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.