Security Resilience

CVE-2026-45066

Sensiolabs Symfony 6.1.0 – 6.4.40

Published
14 July 2026
Modified
16 July 2026
Patch / advisory
View advisory
CVSS Score v4 2.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0034 26th percentile
Risk Priority 15 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-45066 is a low-severity Incomplete List of Disallowed Inputs (CWE-184) vulnerability in Sensiolabs Symfony. Its CVSS base score is 2.3 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Security Account Manager (T1003.002); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A06:2025 Insecure Design

EU & UK References

Vulnerability Data

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. From 6.1.0-BETA1 until 6.4.40, 7.4.12, and 8.0.12, HtmlSanitizer URL sanitization can allow off-allowlist URLs through allowLinkHosts() or allowMediaHosts() because UrlSanitizer::parse() follows RFC 3986…

more

while browsers follow WHATWG URL parsing, and because <area href> is checked against the media policy rather than the link policy. This issue is fixed in versions 6.4.40, 7.4.12, and 8.0.12.

CWE(s)
CWE-184CWE-436

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
attack.mitre.org →
T1012 Query Registry Discovery
Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.
attack.mitre.org →
T1016.001 Internet Connection Discovery Discovery
Adversaries may check for Internet connectivity on compromised systems.
attack.mitre.org →
T1021.001 Remote Desktop Protocol Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1021.003 Distributed Component Object Model Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1021.004 SSH Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-48736Same product: Sensiolabs Symfony
CVE-2026-45753Same product: Sensiolabs Symfony
CVE-2026-47767Same product: Sensiolabs Symfony
CVE-2026-48747Same product: Sensiolabs Symfony
CVE-2026-45070Same product: Sensiolabs Symfony
CVE-2026-45133Same product: Sensiolabs Symfony
CVE-2026-45077Same product: Sensiolabs Symfony
CVE-2026-47212Same product: Sensiolabs Symfony
CVE-2026-45755Same product: Sensiolabs Symfony
CVE-2026-45073Same product: Sensiolabs Symfony

Affected Assets

sensiolabs
symfony
6.1.0 — 6.4.40 · 7.0.0 — 7.4.12 · 8.0.0 — 8.0.12

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)
  • V3.5.2
  • V4.4.2
  • V16.2.5

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover cases where two products interpret the same inputs or state transitions differently.

SI-10 Information Input Validation good match

SI-10 requires validity checks on inputs, which structurally replaces incomplete deny-lists with complete allow-list or sanitization logic.

SA-8 Security and Privacy Engineering Principles partial match

Applying security engineering principles during design can require unambiguous protocol and data-format specifications that eliminate divergent interpretations between products.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
blocks

Secure SDLC practices directly require complete, positive input validation instead of incomplete denylists.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-436, a class-level weakness, and none of its children carries one either.

References