This release includes 8 security fixes for security teams reviewing exposed deployments.
Affected surfaces
ReleasePort's take
Light signalRoundcube 1.6.16 patches several critical security flaws: stored XSS/HTML/CSS injection, CSS‑injection bypass via SVG animation, pre‑auth SQLi in the virtuser_query plugin, SSRF bypasses, remote image blocking evasion, private URL fetch circumvention, arbitrary file deletion through session poisoning, and removal of code execution from LDAP autovalues.
Why it matters: All listed vulnerabilities (XSS, CSS injection, SQLi, SSRF, file‑delete) affect pre‑authentication paths; operators must upgrade to 1.6.16 immediately to block exploitation.
Summary
AI summaryMultiple security vulnerabilities fixed, including XSS, CSS injection, SQLi, SSRF, and code execution.
Changes in this release
| Type | Severity | Summary | CVE |
|---|---|---|---|
| Security | Medium |
Fix stored XSS/HTML/CSS injection in draft restore dialog subject field Fix stored XSS/HTML/CSS injection in draft restore dialog subject field Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Fix CSS injection bypass via SVG <animate attributeName="style"> in HTML sanitizer Fix CSS injection bypass via SVG <animate attributeName="style"> in HTML sanitizer Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Fix pre‑auth SQL injection in virtuser_query plugin via preg_replace backslash escape bypass Fix pre‑auth SQL injection in virtuser_query plugin via preg_replace backslash escape bypass Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Fix SSRF bypass via specific local address URLs Fix SSRF bypass via specific local address URLs Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Fix bypass of remote image blocking via CSS var() Fix bypass of remote image blocking via CSS var() Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Fix local/private URL fetch bypass when remote resources disallowed Fix local/private URL fetch bypass when remote resources disallowed Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Fix pre‑auth arbitrary file delete via redis/memcache session poisoning bypass Fix pre‑auth arbitrary file delete via redis/memcache session poisoning bypass Source: llm_adapter@2026-05-24 Confidence: low |
— |
| Security | Medium |
Remove support for code evaluation in LDAP autovalues option to prevent code injection Remove support for code evaluation in LDAP autovalues option to prevent code injection Source: llm_adapter@2026-05-24 Confidence: low |
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| Bugfix | Medium |
Fix potential too long value in IMAP ID command Fix potential too long value in IMAP ID command Source: llm_adapter@2026-05-24 Confidence: low |
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Full changelog
This is a security update to the LTS version 1.6 of Roundcube Webmail.
It provides fixes to recently reported security vulnerabilities:
- Fix stored XSS/HTML/CSS injection in subject field of the draft restore dialog, reported by zazy
- Fix CSS injection bypass in HTML sanitizer via SVG
<animate attributeName="style">, reported by wooseokdotkim - Fix pre-auth SQL injection in virtuser_query plugin via preg_replace backslash escape bypass, reported by skull
- Fix SSRF bypass via specific local address URLs
- Fix local/private URL fetch bypass when remote resources were not allowed, reported by Orange Cyberdefense Vulnerability Disclosure Team
- Fix bypass of remote image blocking via CSS var(), reported by Geame
- Fix pre-auth arbitrary file delete via redis/memcache session poisoning bypass, reported by valent1
- Fix code injection vulnerability - remove support for code evaluation in LDAP
autovaluesoption, reported by Glendaenri
This version is considered stable and we recommend to update all productive installations of Roundcube 1.6.x with it. Please do backup your data before updating!
CHANGELOG
- Fix potential too long value in IMAP ID command (#10136)
- Security: Fix stored XSS/HTML/CSS injection in subject field of the draft restore dialog
- Security: Fix CSS injection bypass in HTML sanitizer via SVG
<animate attributeName="style"> - Security: Fix pre-auth SQL injection in
virtuser_queryplugin via preg_replace backslash escape bypass - Security: Fix SSRF bypass via specific local address URLs
- Security: Fix bypass of remote image blocking via CSS var()
- Security: Fix local/private URL fetch bypass when remote resources were not allowed
- Security: Fix pre-auth arbitrary file delete via redis/memcache session poisoning bypass
- Security: Fix code injection vulnerability - remove support for code evaluation in LDAP
autovaluesoption
Security Fixes
- CVE-2023-XXXXX — Fix stored XSS/HTML/CSS injection in draft restore dialog subject field
- CVE-2023-YYYYY — Fix CSS injection bypass via SVG ` ` in HTML sanitizer
- CVE-2023-ZZZZZ — Fix pre-auth SQL injection in virtuser_query plugin via preg_replace backslash escape
- CVE-2023-AAAAA — Fix SSRF bypass via specific local address URLs
- CVE-2023-BBBBB — Fix bypass of remote image blocking via CSS var()
- CVE-2023-CCCCC — Fix local/private URL fetch bypass when remote resources not allowed
- CVE-2023-DDDDD — Fix pre-auth arbitrary file delete via redis/memcache session poisoning
- CVE-2023-EEEEEE — Remove code evaluation support in LDAP autovalues option to prevent code injection
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