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. 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

6.3CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

5.6CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS

0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-25)

CWE

CWE-290

Published

2026-09-30

Modified

2026-10-02

Record from

the NVD, synced 2026-10-19

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

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