Description
In the RingRTC library before 2.72.0 for Signal, a peer that saturates a call's FSM queue can interfere with the ability of a local hangup to tear the call (with its audio and perhaps also video track) down.
Published: 2026-10-20
Score: 9.3 Critical
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service
Action: Apply Patch
AI Analysis

Impact

A peer in a RingRTC call can overload the library’s finite state machine queue, preventing a local hangup from terminating the call and its associated audio or video streams. This results in a denial of service to the calling party, disrupting session continuity and potentially locking resources. The weakness stems from improper resource exhaustion handling, classified as CWE‑754.

Affected Systems

The vulnerability affects the RingRTC library used by Signal, specifically any version earlier than 2.72.0. Users running the impacted library in any of their applications are susceptible.

Risk and Exploitability

The CVSS score of 9.3 indicates high severity. No EPSS data is available, but the risk remains significant due to the exploitability of a malicious peer. The vulnerability is not listed in the CISA KEV catalog. The likely attack vector is remote, as a compromised or controlled call participant can orchestrate the queue saturation.

Generated by OpenCVE AI on October 20, 2026 at 06:47 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update RingRTC to version 2.72.0 or later, which fixes the queue saturation issue.
  • If upgrading is delayed, implement application‑level throttling to limit the number of enqueued state changes and prevent queue overflow.
  • Monitor FSM queue usage during calls and impose hard limits that terminate or isolate calls exceeding safe thresholds.

Generated by OpenCVE AI on October 20, 2026 at 06:47 UTC.

Tracking

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Advisories

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History

Sat, 31 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
References

Wed, 21 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
First Time appeared Signal
Signal ringrtc
Vendors & Products Signal
Signal ringrtc

Tue, 20 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
References

Tue, 20 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 20 Oct 2026 12:45:00 +0000

Type Values Removed Values Added
Title Denial of Service via FSM Queue Saturation in RingRTC

Tue, 20 Oct 2026 04:45:00 +0000

Type Values Removed Values Added
Description In the RingRTC library before 2.72.0 for Signal, a peer that saturates a call's FSM queue can interfere with the ability of a local hangup to tear the call (with its audio and perhaps also video track) down.
Weaknesses CWE-754
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:N/SA:N/S:P'}

Subscriptions

Signal Ringrtc
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-10-31T14:55:58.521Z

Reserved: 2026-10-20T04:25:09.736Z

Link: CVE-2026-113380

cve-icon Vulnrichment

Updated: 2026-10-31T14:55:58.521Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-20T05:16:54.083

Modified: 2026-10-31T15:16:51.350

Link: CVE-2026-113380

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-21T16:46:36Z

Weaknesses
  • CWE-754

    Improper Check for Unusual or Exceptional Conditions