Medium severity · published Sep 30, 2026
CVE-2026-103397
OpenSave before 2.4.0-beta.1 Authentication Bypass via Spoofed Relay Sender
5.6
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenSave · Liquid-co
before 2.4.0-beta.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103397
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103397
third-party-advisory
https://gist.github.com/mansurmavlankulov/2ca66f95965fb9d4aab353bcf2434cdb
patch
https://github.com/Liquid-co/OpenSave/commit/2f2612b13233ac123e01a03cb3008c44bacaeae3
technical-description
https://github.com/Liquid-co/OpenSave/blob/v2.3.1/internal/p2p/wanclient_handlers.go#L268-L282
product
https://github.com/Liquid-co/OpenSave
third-party-advisory
https://www.vulncheck.com/advisories/opensave-before-2.4.0-beta.1-authentication-bypass-via-spoofed-relay-sender
More from OpenSave
8.1
CVE-2026-103398
OpenSave through 2.4.0 Arbitrary File Read and Write via Peer-Controlled Save Path