SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-24903

libsignal-service-rs is a Rust version of the libsignal-service-java library which implements the core functionality to communicate with Signal servers.

HIGH 8.5EPSS 0.19%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.19%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

libsignal-service-rs is a Rust version of the libsignal-service-java library which implements the core functionality to communicate with Signal servers. Prior to commit 82d70f6720e762898f34ae76b0894b0297d9b2f8, any contact may forge a sync message, impersonating another device of the local user. The origin of sync messages is not checked. Patched libsignal-service can be found after commit 82d70f6720e762898f34ae76b0894b0297d9b2f8. The `Metadata` struct contains an additional `was_encrypted` field, which breaks the API, but should be easily resolvable. No known workarounds are available.

CVSS 3.1
8.5 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
EPSS
0.19% probability · 8th percentile
CISA KEV
Not listed
Weakness
CWE-345
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.