CVE Intelligence
Medium

CVE-2026-48760 — Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0 until 6.4.41, 7.4.13, and 8.0.13, UrlSanitizer::parse() rejected raw BiDi formatting characters but not percent-encoded forms and used an ASCII-only whitespace check, allowing sanitized URLs to retain visual-spoofing characters that downstream consumers could decode or display. This issue is fixed in versions 6.4.41, 7.4.13, and 8.0.13.

Published Jul 14, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Sensiolabs
Symfony and 1 more
CVSS base
6.1
Medium · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Sensiolabs Symfony, Symfony Html-sanitizer, Symfony Symfony).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  5. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Sensiolabs Symfony ≥ 6.1.0 and < 6.4.41≥ 7.0.0 and < 7.4.13≥ 8.0.0 and < 8.0.13 Vulnerable NIST National Vulnerability Database
Symfony Html-sanitizer version >= 6.1.0, < 6.4.41version >= 7.0.0-BETA1, < 7.4.13version >= 8.0.0-BETA1, < 8.0.13 Vulnerable CVE Program (cve.org) e CISA ADP
Symfony Symfony version >= 6.1.0, < 6.4.41version >= 7.0.0-BETA1, < 7.4.13version >= 8.0.0-BETA1, < 8.0.13 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 4.0 Medium — — security-advisories@github.com via NIST National Vulnerability Database
5.3 CVSS 4.0 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
6.1 CVSS 3.1 Medium 2.8 2.7 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-451

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · symfony/symfony, symfony/html-sanitizer
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • Fix documented
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVSS changed · 6.1
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Jul 14, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

5 on the record

Elsewhere on this site

Sensiolabs
every CVE for this vendor
CWE-451
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-109449 Symfony: Unbounded Nesting in the Expression Parser Lets Untrusted Expressions Crash the Process 6h
  • CVE-2026-109413 Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process 7h
  • CVE-2026-108082 Symfony: ReDoS in HeaderUtils::split() Reachable Through the Cache-Control Request Header 7h
  • CVE-2026-48747 Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade Jul 14, 2026
  • CVE-2026-48761 Symfony: HtmlSanitizer UrlAttributeSanitizer Misses URL Attributes on <object>, <applet>, <iframe>, <img> and the URL Inside <meta http-equiv="refresh"> content Jul 14, 2026
  • CVE-2026-48784 Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization Jul 14, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-48760 is "Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense", rated Medium. It affects Symfony (Sensiolabs); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.1 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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