Skip to main content
VulnerabilityPublished

CVE-2026-121949: sensiolabs symfony · Incomplete List of Disallowed Inputs

Affects sensiolabs symfonySource CVE Database V5

0
Compare

Not known to be exploited · CVSS 2.3 Low · fixed in 8.1.11 : update sensiolabs symfony when convenient.

Data as of 5 Nov 2026, 18:05 UTC

CVSS 4.0 base score
2.3Low
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (Checkmarx)CVSS 4.02.3
Patch
Available – fixed in 8.1.11, 7.4.23, 6.4.50
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 5 Nov 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

What to do

Upgrade symfony and symfony/html-sanitizer to 8.1.11, 7.4.23 or 6.4.50.

Affected software

ProductAffectedFixed in
symfonysymfony/html-sanitizerAffected
  • >=8.0.0 <8.1.11
Fixed in
  • 8.1.11
symfonysymfony/html-sanitizerAffected
  • >=7.0.0 <7.4.23
Fixed in
  • 7.4.23
symfonysymfony/html-sanitizerAffected
  • >=6.1.0 <6.4.50
Fixed in
  • 6.4.50
Packagistsymfony/html-sanitizerpkg:composer/symfony/html-sanitizerOther threatsAffected
  • >=6.1.0 <6.4.50
  • >=7.0.0 <7.4.23
  • >=8.0.0 <8.1.11
Fixed in
  • 6.4.50
  • 7.4.23
  • 8.1.11

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Symfony HtmlSanitizer to version 6.4.50, 7.4.23, or 8.1.11 or later, where this issue is fixed. These versions properly validate URLs in srcset and imagesrcset attributes according to the configured media schemes and hosts allowlists. No other mitigation is required if the upgrade is applied.

Description

Symfony HtmlSanitizer versions prior to 6.4.50, 7.4.23, and 8.1.11 do not properly validate URLs in the srcset and imagesrcset attributes, allowing disallowed hosts or schemes to bypass media URL policies. This can cause browsers to load images from untrusted sources, potentially enabling user tracking or IP logging without authentication.

References

Community reviews

Loading reviews…