DEBIAN-CVE-2026-55950

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Source

https://security-tracker.debian.org/tracker/CVE-2026-55950

Import Source

https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55950.json

JSON Data

https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-55950

Upstream

CVE-2026-55950

Published

2026-07-02T17:17:02.910Z

Modified

2026-07-03T12:00:16.598096411Z

Severity

8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X CVSS Calculator

Summary

[none]

Details

Time-of-check Time-of-use (TOCTOU) race condition vulnerability in Erlang/OTP ssl (dtlspacketdemux module) allows an unauthenticated remote attacker to crash all active DTLS sessions on a listener. A DTLS server listener uses a single shared dtlspacketdemux genserver process to route incoming UDP datagrams to the correct connection handler. When a DTLS client reconnects rapidly from the same source address and port (sending multiple ClientHello messages in quick succession), a race condition in the demux's internal gbtrees key-value store causes a {keyexists, {old, Client}} crash, terminating the demux process. Because the demux is shared across all DTLS associations on that listener, its crash immediately kills every active DTLS session, not just the attacker's. The attack is pre-authentication: the attacker only needs to send UDP datagrams containing valid ClientHello messages from the same source IP and port before the intermediate DOWN monitor message is processed by the genserver. No credentials, no completed handshake, and no special configuration are required, and the crash can be repeated indefinitely to create a persistent denial of service for all clients of that listener. This vulnerability is associated with program file lib/ssl/src/dtlspacketdemux.erl. This issue affects OTP from OTP 25.3 before 29.0.3, 28.5.0.3, and 27.3.4.14 corresponding to ssl from 10.9 before 11.7.3, 11.6.0.3, and 11.2.12.10.

References

https://security-tracker.debian.org/tracker/CVE-2026-55950

Affected packages

Debian:11 / erlang

Package

Name: erlang
Purl: pkg:deb/debian/erlang?arch=source&distro=bullseye

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:23.*

1:23.2.6+dfsg-1

1:23.2.6+dfsg-1+deb11u1

1:23.2.6+dfsg-1+deb11u2

1:23.2.6+dfsg-1+deb11u3

1:23.2.6+dfsg-1+deb11u4

1:24.*

1:24.0~rc1+dfsg-1

1:24.0~rc2+dfsg-1

1:24.0~rc3+dfsg-1

1:24.0.2+dfsg-1

1:24.0.3+dfsg-1

1:24.0.4+dfsg-1

1:24.0.5+dfsg-1

1:24.0.5+dfsg-2

1:24.0.6+dfsg-1

1:24.0.6+dfsg-2

1:24.1+dfsg-1

1:24.1.1+dfsg-1

1:24.1.4+dfsg-1

1:24.1.5+dfsg-1

1:24.1.7+dfsg-1

1:24.2+dfsg-1

1:24.2.1+dfsg-1

1:24.2.2+dfsg-1

1:24.3+dfsg-1

1:24.3.1+dfsg-1

1:24.3.2+dfsg-1

1:24.3.3+dfsg-1

1:24.3.4+dfsg-1

1:24.3.4.1+dfsg-1

1:24.3.4.5+dfsg-1

1:25.*

1:25.0~rc1+dfsg-1

1:25.0~rc2+dfsg-1

1:25.0~rc3+dfsg-1

1:25.0+dfsg-1

1:25.0.2+dfsg-1

1:25.0.3+dfsg-1

1:25.0.4+dfsg-1

1:25.1.1+dfsg-1

1:25.1.2+dfsg-1

1:25.2+dfsg-1

1:25.2.1+dfsg-1

1:25.2.1+dfsg-2

1:25.2.2+dfsg-1

1:25.2.3+dfsg-1

1:25.3.2.8+dfsg-1

1:25.3.2.10+dfsg-1

1:25.3.2.10+dfsg-2

1:25.3.2.11+dfsg-1

1:25.3.2.12+dfsg-1

1:25.3.2.12+dfsg-2

1:25.3.2.12+dfsg-3

1:26.*

1:26.0~rc2+dfsg-1

1:26.0~rc3+dfsg-1

1:26.0+dfsg-1

1:26.0.1+dfsg-1

1:26.0.2+dfsg-1

1:26.1.2+dfsg-1

1:26.2.1+dfsg-1

1:26.2.4+dfsg-1

1:27.*

1:27.0~rc3+dfsg-1

1:27.0~rc3+dfsg-2

1:27.0~rc3+dfsg-3

1:27.0~rc3+dfsg-4

1:27.0+dfsg-1

1:27.0.1+dfsg-1

1:27.0.1+dfsg-2

1:27.0.1+dfsg-3

1:27.1.2+dfsg-1

1:27.2+dfsg-1

1:27.2+dfsg-2

1:27.2+dfsg-3~exp1

1:27.2.1+dfsg-1

1:27.2.1+dfsg-2

1:27.2.2+dfsg-1

1:27.2.3+dfsg-1

1:27.2.4+dfsg-1

1:27.3+dfsg-1

1:27.3.1+dfsg-1

1:27.3.2+dfsg-1

1:27.3.3+dfsg-1

1:27.3.4+dfsg-1

1:27.3.4.1+dfsg-1

1:27.3.4.3+dfsg-1

1:27.3.4.4+dfsg-1

1:27.3.4.6+dfsg-1

1:27.3.4.8+dfsg-1

1:27.3.4.9+dfsg-1

1:27.3.4.10+dfsg-1

1:27.3.4.11+dfsg-1

1:27.3.4.11+dfsg-2

1:27.3.4.11+dfsg-3

1:27.3.4.11+dfsg-4

1:27.3.4.11+dfsg-5

1:27.3.4.11+dfsg-6

1:27.3.4.11+dfsg-7

1:27.3.4.12+dfsg-1

1:28.*

1:28.0+dfsg-1

1:28.0.1+dfsg-1

1:28.0.2+dfsg-1

1:28.0.4+dfsg-1

1:28.1.1+dfsg-1

1:28.2+dfsg-1

1:28.3+dfsg-1

1:28.3.1+dfsg-1

1:29.*

1:29.0~rc1+dfsg-1

1:29.0~rc1+dfsg-2

1:29.0~rc2+dfsg-1

1:29.0~rc3+dfsg-1

1:29.0~rc3+dfsg-2

1:29.0~rc3+dfsg-3

1:29.0~rc3+dfsg-4

1:29.0+dfsg-1

1:29.0+dfsg-2

1:29.0.1+dfsg-1

1:29.0.2+dfsg-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55950.json"

Debian:12 / erlang

Package

Name: erlang
Purl: pkg:deb/debian/erlang?arch=source&distro=bookworm

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:25.*

1:25.2.3+dfsg-1

1:25.2.3+dfsg-1+deb12u1

1:25.2.3+dfsg-1+deb12u2

1:25.2.3+dfsg-1+deb12u3

1:25.2.3+dfsg-1+deb12u4

1:25.3.2.8+dfsg-1

1:25.3.2.10+dfsg-1

1:25.3.2.10+dfsg-2

1:25.3.2.11+dfsg-1

1:25.3.2.12+dfsg-1

1:25.3.2.12+dfsg-2

1:25.3.2.12+dfsg-3

1:26.*

1:26.0~rc2+dfsg-1

1:26.0~rc3+dfsg-1

1:26.0+dfsg-1

1:26.0.1+dfsg-1

1:26.0.2+dfsg-1

1:26.1.2+dfsg-1

1:26.2.1+dfsg-1

1:26.2.4+dfsg-1

1:27.*

1:27.0~rc3+dfsg-1

1:27.0~rc3+dfsg-2

1:27.0~rc3+dfsg-3

1:27.0~rc3+dfsg-4

1:27.0+dfsg-1

1:27.0.1+dfsg-1

1:27.0.1+dfsg-2

1:27.0.1+dfsg-3

1:27.1.2+dfsg-1

1:27.2+dfsg-1

1:27.2+dfsg-2

1:27.2+dfsg-3~exp1

1:27.2.1+dfsg-1

1:27.2.1+dfsg-2

1:27.2.2+dfsg-1

1:27.2.3+dfsg-1

1:27.2.4+dfsg-1

1:27.3+dfsg-1

1:27.3.1+dfsg-1

1:27.3.2+dfsg-1

1:27.3.3+dfsg-1

1:27.3.4+dfsg-1

1:27.3.4.1+dfsg-1

1:27.3.4.3+dfsg-1

1:27.3.4.4+dfsg-1

1:27.3.4.6+dfsg-1

1:27.3.4.8+dfsg-1

1:27.3.4.9+dfsg-1

1:27.3.4.10+dfsg-1

1:27.3.4.11+dfsg-1

1:27.3.4.11+dfsg-2

1:27.3.4.11+dfsg-3

1:27.3.4.11+dfsg-4

1:27.3.4.11+dfsg-5

1:27.3.4.11+dfsg-6

1:27.3.4.11+dfsg-7

1:27.3.4.12+dfsg-1

1:28.*

1:28.0+dfsg-1

1:28.0.1+dfsg-1

1:28.0.2+dfsg-1

1:28.0.4+dfsg-1

1:28.1.1+dfsg-1

1:28.2+dfsg-1

1:28.3+dfsg-1

1:28.3.1+dfsg-1

1:29.*

1:29.0~rc1+dfsg-1

1:29.0~rc1+dfsg-2

1:29.0~rc2+dfsg-1

1:29.0~rc3+dfsg-1

1:29.0~rc3+dfsg-2

1:29.0~rc3+dfsg-3

1:29.0~rc3+dfsg-4

1:29.0+dfsg-1

1:29.0+dfsg-2

1:29.0.1+dfsg-1

1:29.0.2+dfsg-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55950.json"

Debian:13 / erlang

Package

Name: erlang
Purl: pkg:deb/debian/erlang?arch=source&distro=trixie

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:27.*

1:27.3.4.1+dfsg-1

1:27.3.4.1+dfsg-1+deb13u1

1:27.3.4.1+dfsg-1+deb13u2

1:27.3.4.3+dfsg-1

1:27.3.4.4+dfsg-1

1:27.3.4.6+dfsg-1

1:27.3.4.8+dfsg-1

1:27.3.4.9+dfsg-1

1:27.3.4.10+dfsg-1

1:27.3.4.11+dfsg-1

1:27.3.4.11+dfsg-2

1:27.3.4.11+dfsg-3

1:27.3.4.11+dfsg-4

1:27.3.4.11+dfsg-5

1:27.3.4.11+dfsg-6

1:27.3.4.11+dfsg-7

1:27.3.4.12+dfsg-1

1:28.*

1:28.0+dfsg-1

1:28.0.1+dfsg-1

1:28.0.2+dfsg-1

1:28.0.4+dfsg-1

1:28.1.1+dfsg-1

1:28.2+dfsg-1

1:28.3+dfsg-1

1:28.3.1+dfsg-1

1:29.*

1:29.0~rc1+dfsg-1

1:29.0~rc1+dfsg-2

1:29.0~rc2+dfsg-1

1:29.0~rc3+dfsg-1

1:29.0~rc3+dfsg-2

1:29.0~rc3+dfsg-3

1:29.0~rc3+dfsg-4

1:29.0+dfsg-1

1:29.0+dfsg-2

1:29.0.1+dfsg-1

1:29.0.2+dfsg-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55950.json"

Debian:14 / erlang

Package

Name: erlang
Purl: pkg:deb/debian/erlang?arch=source&distro=forky

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1:27.*

1:27.3.4.1+dfsg-1

1:27.3.4.3+dfsg-1

1:27.3.4.4+dfsg-1

1:27.3.4.6+dfsg-1

1:27.3.4.8+dfsg-1

1:27.3.4.9+dfsg-1

1:27.3.4.10+dfsg-1

1:27.3.4.11+dfsg-1

1:27.3.4.11+dfsg-2

1:27.3.4.11+dfsg-3

1:27.3.4.11+dfsg-4

1:27.3.4.11+dfsg-5

1:27.3.4.11+dfsg-6

1:27.3.4.11+dfsg-7

1:27.3.4.12+dfsg-1

1:28.*

1:28.0+dfsg-1

1:28.0.1+dfsg-1

1:28.0.2+dfsg-1

1:28.0.4+dfsg-1

1:28.1.1+dfsg-1

1:28.2+dfsg-1

1:28.3+dfsg-1

1:28.3.1+dfsg-1

1:29.*

1:29.0~rc1+dfsg-1

1:29.0~rc1+dfsg-2

1:29.0~rc2+dfsg-1

1:29.0~rc3+dfsg-1

1:29.0~rc3+dfsg-2

1:29.0~rc3+dfsg-3

1:29.0~rc3+dfsg-4

1:29.0+dfsg-1

1:29.0+dfsg-2

1:29.0.1+dfsg-1

1:29.0.2+dfsg-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55950.json"