https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-09-29T15:54:40.721807+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2026-42258 CVE-2026-42258 — net-imap: Command Injection via unvalidated Symbol inputs 2026-09-29T15:54:40.742989+00:00

Affected: ruby net-imap, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 7 Extended Lifecycle Support, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On, Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On, Red Hat Enterprise Linux 8.8 Telecommunications Update Service and 11 more

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, symbol arguments to commands are vulnerable to a CRLF Injection / IMAP Command injection via Symbol arguments passed to IMAP commands. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.

 https://vulnerability.circl.lu/vuln/ghsa-75xq-5h9v-w6px GHSA-75xq-5h9v-w6px — net-imap vulnerable to command Injection via unvalidated Symbol inputs 2026-09-29T15:54:40.743166+00:00

Affected: RubyGems: net-imap

### Summary

Symbol arguments to commands are vulnerable to a CRLF Injection / IMAP Command injection via Symbol arguments passed to IMAP commands.

### Details

Symbol arguments represent IMAP "system flags", which are formatted as "atoms" (with no quoting) with a `"\"` prefix. Vulnerable versions of Net::IMAP sends the symbol name directly to the socket, with no validation.

Because the Symbol input is unvalidated, it could contain invalid `flag` characters, including `SP` and `CRLF`, which could be used to finish the current command and inject new commands.

Although IMAP `flag` arguments are only valid input for a few IMAP commands, most Net::IMAP commands use generic argument handling, and will allow Symbol (`flag`) inputs.

Note also that the list of valid symbol inputs should be restricted to an enumerated set of standard RFC defined flag types, which have each been given specific defined semantics. Any user-provided values outside of that list of standard "system flags" needs to use the IMAP `keyword` syntax, which are sent as atoms, i.e: string inputs. Under no circumstances should `#to_sym` ever be called on unvetted user-provided input: that will always be a bug in the calling code for the simple reason that `user_input_atom` is as `\user_input_atom`.

For forward compatibility with future IMAP extentions, Net::IMAP, does not restrict flag inputs to an enumerated list. That is the responsibility of the calling application code, which knows which flag semantics…