FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

erlang -- SSH plaintext recovery attack against CBC ciphers

Affected packages
	erlang	<	28.5.0.5,4
	erlang-runtime27	<	27.3.4.16
	erlang-runtime28	<	28.5.0.5
	erlang-runtime29	<	29.0.5

Details

VuXML ID	0b58454e-8ff3-11f1-b35c-4c526214c986
Discovery	2026-07-30
Entry	2026-08-04

The Erlang/OTP team reports:

The SSH client and server now reject incoming packets not aligned to the cipher block size as required by RFC 4253 section 6. For CBC ciphers, a timing-safe "packet discard" mechanism (CVE-2008-5161 mitigation) ensures structural errors are indistinguishable from MAC failures before disconnecting. AEAD and encrypt-then-MAC modes disconnect immediately.

[source]

References

CVE Name	CVE-2008-5161
URL	https://github.com/erlang/otp/pull/11110
URL	https://nvd.nist.gov/vuln/detail/CVE-2008-5161