Home / mailings

PDF

[USN-8478-1] Ruby vulnerabilities

Posted on 30 June 2026
Ubuntu Security

==========================================================================Ubuntu Security Notice USN-8478-1
June 29, 2025

ruby2.7, ruby3.0, ruby3.2, ruby3.3 vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 26.04 LTS
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Ruby could allow unintended access to network services.

Software Description:
- ruby3.3: Object-oriented scripting language
- ruby3.2: Object-oriented scripting language
- ruby3.0: Object-oriented scripting language
- ruby2.7: Object-oriented scripting language

Details:

It was discovered that Ruby's Net::IMAP library did not properly verify
that TLS encryption was started after issuing a STARTTLS command. A remote
attacker could use this to perform a machine-in-the-middle attack and silently
bypass TLS encryption. (CVE-2026-42246)

It was discovered that Ruby's Net::IMAP library did not validate
string arguments passed to certain commands. A remote attacker could use
this to inject arbitrary IMAP commands. (CVE-2026-42257)

It was discovered that Ruby's Net::IMAP library was vulnerable to a
denial of service attack when authenticating with SCRAM-SHA1 or
SCRAM-SHA256. A hostile server could send a very large iteration count
value to cause excessive computation in the client. This issue only
affected ruby3.3. (CVE-2026-42256)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 26.04 LTS
libruby3.3 3.3.8-2ubuntu3.1
ruby3.3 3.3.8-2ubuntu3.1

Ubuntu 24.04 LTS
libruby3.2 3.2.3-1ubuntu0.24.04.8
ruby3.2 3.2.3-1ubuntu0.24.04.8

Ubuntu 22.04 LTS
libruby3.0 3.0.2-7ubuntu2.13
ruby3.0 3.0.2-7ubuntu2.13

Ubuntu 20.04 LTS
libruby2.7 2.7.0-5ubuntu1.18+esm5
Available with Ubuntu Pro
ruby2.7 2.7.0-5ubuntu1.18+esm5
Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-8478-1
CVE-2026-42246, CVE-2026-42256, CVE-2026-42257

Package Information:
https://launchpad.net/ubuntu/+source/ruby3.3/3.3.8-2ubuntu3.1
https://launchpad.net/ubuntu/+source/ruby3.2/3.2.3-1ubuntu0.24.04.8
https://launchpad.net/ubuntu/+source/ruby3.0/3.0.2-7ubuntu2.13

--===============0194499379087679200==Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature

 

TOP