## Release 1.6.21

- Security: Fix open redirect via IMAP error recovery on attachment get
- Security: Fix so Received: header includes only trusted hostname and forwarded IP from a trusted proxy
- Security: Fix bug where some managesieve destructive actions could have been triggered cross-site via GET
- Security: Fix Sieve script injection via a rule operator
- Security: Fix Sieve script injection via set/include modifiers
- Security: Fix bug where resolve_url() ignored trusted host setting
- Security: Fix mail header injection via a MDN subject
- Security: Fix HTTP request injection via the spellcheck ATD backend
- Security: Fix IMAP command injection via CRLF in _uid parameter with messages_cache enabled
- Security: Fix SSRF in CSS proxy via incomplete is_local_url() nip.io/sslip.io bypass
- Security: Fix CSRF validation bypass for file-only POST requests
- Security: Fix `disabled_actions` restriction bypass by writing '_' instead of '-' in the action name
- Security: Fix CSRF validation bypass for mail purge/expunge commands
- Security: Fix passing potentally unsafe attachment content into ImageMagick on image type conversion
- Security: Fix Unbounded CPU loop/DoS in rcube_session::unserialize() via a negative length token
- Security: Fix SSRF filter (is_local_url()) bypass via 6to4 (2002::/16) addresses
- Security: Fix so IMAP host input is validated more strictly

## Release 1.6.20

- Security: Fix IMAP command injection via CRLF in `_uid` parameter of mail/headers and mail/viewsource action
- Security: Fix bug where an alias login wasn't qualified by IMAP host
- Security: Add a size limit to the CSS proxy content processing
- Security: Fix SSRF filter (is_local_url()) bypass via NAT64 64:ff9b::/96
- Security: Fix remote content blocking bypass via SVG SMIL `by` attribute
- Security: Fix remote content blocking bypass via CSS escapes in FuncIRI attributes (again)
- Security: Fix passing potentally unsafe attachment content into ImageMagick on image resize
- Security: Fix mail header injection via the From display-name in the Bounce (resend) action
- Security: Fix mail header injection via References/In-Reply-To/Message-ID/From parameters
- Security: Fix object injection primitive in rcube_session::unserialize() via "!"-prefixed session keys
- Security: Fix ImageMagick resource limits bypass by GD fallback during thumbnail generation
- Security: Fix CSS scoping bypass in HTML messages using at-rules
- Security: Fix bug where deprecated action aliases bypassed `disabled_actions` setting
- Security: Fix IMAP command injection via CRLF in `_flag` parameter of mail/mark action
- Security: Fix CSRF validation bypass in the mark-as-junk action
- Security: Fix XSS issue in handling of password driver error responses
- Security: Fix mail header injection via subject of a message forwarded as attachment
- Security: Fix mail header injection via media type in an inline image data URI
- Security: Fix bug where Password Modoboa driver could change password for another account
- Security: Fix unsafe use of a login name in SquirrelMail import file path

## Release 1.6.19

- Fix PHP Warning: Undefined variable $tmp_command in .../plugins/markasjunk/drivers/cmd_learn.php (#10294)
- Security: Fix CSS declaration smuggling via un-encoded ampersand emission
- Security: Fix CSS property injection via body `background` attribute
- Security: Fix email header injection via bare CR in the subject field
- Security: Fix email header injection via C-escape \r in the recipient display name
- Security: Fix email header injection via identity's organization field
- Security: Fix zero-click stored XSS via TNEF MIME tag injection in the attachment URL
- Security: Fix XSS in the HTML editor using text/enriched part content
- Security: Fix cross-user access in contact group membership (add/remove) in the SQL address book
- Security: Fix is_local_url() bypass via trailing-dot FQDN in stylesheet URL
- Security: Fix remote content blocking bypass via CSS escapes in FuncIRI attributes
- Security: Fix remote-content blocker bypass via SVG SMIL src animation
- Security: Fix SSRF bypass in Roundcube CSS proxy via hexadecimal IPv6-mapped IPv4 addresses

## Release 1.6.18

- Password: Fix fatal error "Class 'Zxcvbn' not found" (#10274)
- Fix out-of-bounds string reads on truncated compressed-RTF in the TNEF decoder (#10269)
- Security: Add basic validation for content proxied by the css proxy
- Security: Fix SSRF bypass via specific local address URLs using 100.64.0.0/10 and fe80::/10 nets
- Security: Fix SSRF filter bypass via various forms of nip.io/sslip.io hostnames evading is_local_url() check
- Security: Fix remote content blocking bypass via unclosed url() in a FuncIRI attribute
- Security: Fix LDAP filter injection via unescaped %u/%fu/%d substitution into the `search_filter`
- Security: Fix arbitrary Sieve script injection via a filter rule name bypassing `managesieve_disabled_actions`
- Security: Fix RCE via `cmd_learn` driver of markasjunk plugin
- Security: Fix IMAP command injection via mail search and LITERAL+ byte-count desynchronization
- Security: Fix password's modoboa driver leak of an authentication token to a user-controlled host
- Security: Fix stored XSS in "Add to address book" action
- Security: Fix HTML/CSS sanitization bypass via SVG animate `by` attribute