DEBIAN-CVE-2026-27624

Source
https://security-tracker.debian.org/tracker/CVE-2026-27624
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27624.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-27624
Upstream
Published
2026-02-25T05:17:25.380Z
Modified
2026-02-28T10:11:57.142384Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
Summary
[none]
Details

Coturn is a free open source implementation of TURN and STUN Server. Coturn is commonly configured to block loopback and internal ranges using "denied-peer-ip" and/or default loopback restrictions. CVE-2020-26262 addressed bypasses involving "0.0.0.0", "[::1]" and "[::]", but IPv4-mapped IPv6 is not covered. When sending a "CreatePermission" or "ChannelBind" request with the "XOR-PEER-ADDRESS" value of "::ffff:127.0.0.1", a successful response is received, even though "127.0.0.0/8" is blocked via "denied-peer-ip". The root cause is that, prior to the updated fix implemented in version 4.9.0, three functions in "src/client/nsturnioaddr.c" do not check "IN6ISADDRV4MAPPED". "ioaaddrisloopback()" checks "127.x.x.x" (AFINET) and "::1" (AFINET6), but not "::ffff:127.0.0.1." "ioaaddriszero()" checks "0.0.0.0" and "::", but not "::ffff:0.0.0.0." "addrlesseq()" used by "ioaaddrinrange()" for "denied-peer-ip" matching: when the range is AFINET and the peer is AFINET6, the comparison returns 0 without extracting the embedded IPv4. Version 4.9.0 contains an updated fix to address the bypass of the fix for CVE-2020-26262.

References

Affected packages

Debian:11 / coturn

Package

Name
coturn
Purl
pkg:deb/debian/coturn?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*
4.5.2-3
4.5.2-3.1
4.6.1-1
4.6.1-2

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27624.json"

Debian:12 / coturn

Package

Name
coturn
Purl
pkg:deb/debian/coturn?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*
4.6.1-1
4.6.1-2

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27624.json"

Debian:13 / coturn

Package

Name
coturn
Purl
pkg:deb/debian/coturn?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*
4.6.1-2

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27624.json"

Debian:14 / coturn

Package

Name
coturn
Purl
pkg:deb/debian/coturn?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

4.*
4.6.1-2

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27624.json"