DEBIAN-CVE-2026-55953

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Source
https://security-tracker.debian.org/tracker/CVE-2026-55953
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55953.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-55953
Upstream
Published
2026-07-27T16:17:49Z
Modified
2026-09-08T09:00:19Z
Severity
  • 7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
[none]
Details

The Erlang/OTP ssl TLS 1.2 (and earlier) and DTLS client does not verify that the cipher suite selected by the server in ServerHello was among the suites offered by the client in ClientHello. The client-side tls_handshake:hello/5 handler validates the negotiated protocol version and the downgrade sentinel but hands the server-chosen suite directly to ssl_handshake:handle_server_hello_extensions/9, which installs it without a membership check. The TLS 1.3 client path performs this check (per RFC 8446), so it is not affected. An on-path attacker between the client and the intended server can respond with a ServerHello selecting an anonymous key exchange suite such as TLS_DH_anon_* or TLS_ECDH_anon_* that the client never offered. Anonymous suites do not require the server to present a certificate, so the entire verify_peer and cacerts configuration is bypassed: the attacker completes the handshake with its own ephemeral parameters, no certificate is validated, no hostname is checked, and ssl:connect returns {ok, Socket}. All subsequent application traffic is readable and modifiable by the attacker. This issue affects OTP from OTP 17.0 before OTP 27.3.4.15, from OTP 28.0 before OTP 28.5.0.4, and from OTP 29.0 before OTP 29.0.4, corresponding to ssl from 5.3.4 before 11.2.12.11, from 11.3 before 11.6.0.4, and from 11.7 before 11.7.4. Whether OTP before OTP 17.0, corresponding to ssl before 5.3.4, is affected is unknown.

References

Affected packages

Debian:12 / erlang

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown 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
1:29.0.3+dfsg-1
1:29.0.4+dfsg-1
1:29.0.6+dfsg-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55953.json"

Debian:13 / erlang

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1:27.3.4.1+dfsg-1+deb13u3

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

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55953.json"

Debian:14 / erlang

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1:29.0.4+dfsg-1

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
1:29.0.3+dfsg-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55953.json"