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🛡️ CVE-2026-45064 — symfony

🟡 CVSS 6.1 — Medium ✅ No Known Exploit CWE-451 NVD
6.1
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Symfony's HtmlSanitizer URL Attributes Pass Through BiDi Override Characters → Visual href Spoofing

Description

Symfony\Component\HtmlSanitizer\TextSanitizer\UrlSanitizer::parse() (used by UrlSanitizer::sanitize() and therefore by every HtmlSanitizer config that allows links or media) accepts URLs that contain Unicode explicit-direction BiDi formatting characters: U+202A–U+202E (LRE / RLE / PDF / LRO / RLO) and U+2066–U+2069 (LRI / RLI / FSI / PDI). These characters are passed through unchanged into the href / src attributes produced by HtmlSanitizer. When the resulting HTML is rendered in a browser, the override characters reverse or alter the visual ordering of the URL text, so the displayed link can differ arbitrarily from the actual destination: a classic visual-spoofing / phishing primitive against viewers of sanitized content.

Resolution

UrlSanitizer::parse() now rejects URLs containing the explicit-direction BiDi formatting code points (U+202A–U+202E, U+2066–U+2069) before invoking the underlying URL parser. As an unrelated companion fix in the same patch, spaces inside path/query/fragment are now percent-encoded rather than rejected outright, while spaces in the scheme/authority remain rejected by the post-encoding whitespace check.

The patch for this issue is available [here](https://github.com/symfony/symfony/commit/743a435e948b897ef2b5564ac438d4beb95d2526) for branch 5.4.

Credits

Symfony would like to thank Himanshu Anand for reporting the issue and Nicolas Grekas for providing the fix.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity low, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Changed — a successful attack reaches components beyond the vulnerable one.
  • Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
  • Integrity impact: Low — limited, and the attacker does not choose what is affected.
  • Availability impact: None.

Weakness class

CVE-2026-45064 is classified as CWE-451: User Interface (UI) Misrepresentation of Critical Information. The user interface (UI) does not properly represent critical information to the user, allowing the information - or its source - to be obscured or spoofed. This is often a component in phishing attacks.

Affected software

CVE-2026-45064 is recorded against 3 packages.

  • symfony (from 8.0.0 up to 8.0.12)
  • symfony/html-sanitizer (from 8.0.0 up to 8.0.12)
  • symfony/symfony (from 8.0.0 up to 8.0.12)

Timeline and source

Published on 14 July 2026 and last revised on 21 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
github.com
github.com

Other advisories for this package

symfony has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-451: User Interface (UI) Misrepresentation of Critical Information) in other software:

CVE-2026-45064 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity MEDIUM
CVSS Score 6.1
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE CWE-451
Public Exploit ✅ No
Source NVD
Published 2026-07-14
Updated 2026-08-20
Modified 2026-07-21

Affected Packages

Software From version Fixed in
symfony 8.0.0 8.0.12
symfony/html-sanitizer 8.0.0 8.0.12
symfony/symfony 8.0.0 8.0.12

Similar Threats

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