Packages
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)
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
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
| Ubuntu Release | Package Version | ||
|---|---|---|---|
| 26.04 LTS resolute | libruby3.3 – 3.3.8-2ubuntu3.1 | ||
| ruby3.3 – 3.3.8-2ubuntu3.1 | |||
| 24.04 LTS noble | libruby3.2 – 3.2.3-1ubuntu0.24.04.8 | ||
| ruby3.2 – 3.2.3-1ubuntu0.24.04.8 | |||
| 22.04 LTS jammy | libruby3.0 – 3.0.2-7ubuntu2.13 | ||
| ruby3.0 – 3.0.2-7ubuntu2.13 | |||
| 20.04 LTS focal | libruby2.7 – 2.7.0-5ubuntu1.18+esm5 | ||
| ruby2.7 – 2.7.0-5ubuntu1.18+esm5 | |||
Reduce your security exposure
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