CVE-2026-121373
2026-11-04
13h17 +00:00
13h17 +00:00
特定のCVEの通知
特定のCVEの変更情報をいち早くお届けします。
CVE の説明
The Symfony HtmlSanitizer component MetaRefreshAttributeSanitizer, introduced to fix CVE-2026-48761, sanitizes the refresh URL of content attributes of meta tags using a regular expression that is too narrow, allowing sanitization to be bypassed, and resulting in potential URL redirection to untrusted sites in Symfony versions 6.1.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.
The shared declarative refresh steps in the WHATWG HTML Standard require a broader approach: the separator after the time may be ASCII whitespace alone, with no ; or ,, and the url= keyword is optional. Directives the browser honours, but the regular expression misses are returned unchanged, so the attacker URL skips UrlSanitizer entirely and both allowLinkSchemes and allowLinkHosts are defeated for the refresh navigation.
This is reachable under any configuration that allows meta with http-equiv and content, including the documented allowStaticElements() preset.
CVE の情報
関連する弱点
| 弱点名 | 出典 | |
|---|---|---|
| Overly Restrictive Regular Expression A regular expression is overly restrictive in a way that does not match all intended values. |
||
| URL Redirection to Untrusted Site The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. |
