CVE-2025-71264Network attack vector

Client crash via incorrect Opus frame size

Published Mar 16, 2026 · Updated Mar 16, 2026

Out-of-bounds access in Mumble before 1.6.870 allows remote attackers to crash the client through crafted stereo Opus audio. AudioOutputSpeech passes the total stereo frame size to opus_decode_float, causing the decoder to treat output buffers as twice their actual size. Unauthenticated network delivery can interrupt the affected client, with no reported confidentiality or integrity impact.

CVSS severity3.7
Low
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds access in Mumble before 1.6.870 allows remote attackers to crash the client through crafted stereo Opus audio. AudioOutputSpeech passes the total stereo frame size to opus_decode_float, causing the decoder to treat output buffers as twice their actual size. Unauthenticated network delivery can interrupt the affected client, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2025-71264
Published
Mar 16, 2026
Updated
Mar 16, 2026
Vendor
Mumble
Product
Mumble
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.6.870

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mumble · Mumbleversion=0 <1.6.870

Published CVSS scores

3.7MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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