PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-12089 aurelienlws CVE debrief

The LWS Optimize – All-in-One Speed Booster & Cache Tools plugin for WordPress is vulnerable to Arbitrary File Read in versions up to, and including, 3.3.19. This is due to the combine_current_css() function trusting <link rel='stylesheet' href='...'> values harvested from page HTML and converting same-site URLs to absolute filesystem paths before reading them with file_get_contents()/Minify/CSS::add(), without enforcing that the resolved path stay within ABSPATH or have a .css extension. This makes it possible for authenticated attackers, with Editor-level access and above, to read arbitrary files.

Vendor
aurelienlws
Product
LWS Optimize – All-in-One Speed Booster & Cache Tools
CVSS
MEDIUM 4.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-13
Original CVE updated
2026-06-15
Advisory published
2026-06-13
Advisory updated
2026-06-15

Who should care

Users of the LWS Optimize – All-in-One Speed Booster & Cache Tools plugin for WordPress, particularly those with Editor-level access and above, should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability exists in the combine_current_css() function, which trusts <link rel='stylesheet' href='...'> values harvested from page HTML and converts same-site URLs to absolute filesystem paths before reading them with file_get_contents()/Minify/CSS::add(). The function does not enforce that the resolved path stay within ABSPATH or have a .css extension, allowing authenticated attackers with Editor-level access and above to read arbitrary files.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update the LWS Optimize – All-in-One Speed Booster & Cache Tools plugin to a version that fixes this vulnerability.
  • Restrict access to the plugin's functionality to prevent authenticated attackers with Editor-level access and above from exploiting the vulnerability.
  • Monitor the plugin's logs for any suspicious activity related to file reads.

Evidence notes

The vulnerability was reported by [email protected] and is tracked in the Wordfence threat intelligence database.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-12089 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-12089

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-12089 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-12089

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/browser/lws-optimize/tags/3.3.19/Classes/Front/LwsOptimizeCSSManager.php

    [email protected]

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/browser/lws-optimize/tags/3.3.19/Classes/Front/LwsOptimizeCSSManager.php

    [email protected]

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.