{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-15421 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-15421 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-15421 is a medium-severity cross-site scripting vulnerability in siteground Speed Optimizer – The All-In-One Performance-Boosting Plugin, published on 19 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-15421 and fix it if it is affected.\n\nWhat it is: CVE-2026-15421 is a medium-severity cross-site scripting vulnerability in siteground Speed Optimizer – The All-In-One Performance-Boosting Plugin, published on 19 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-15421 in the wild and no public exploit code.\n\nAffected product: siteground Speed Optimizer – The All-In-One Performance-Boosting Plugin. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-15421/ (Markdown: https://insights.sbomify.com/CVE-2026-15421/index.md)","id":"CVE-2026-15421","markdown":"https://insights.sbomify.com/CVE-2026-15421/index.md","name":"CVE-2026-15421","record":{"aliases":["GHSA-8r64-rxjj-mp32"],"analysis":{"component_type":"cms_plugin","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":true,"product_category":"WordPress plugin","requires_auth":"low_privilege","summary":"Authenticated contributors can inject arbitrary scripts via image tags in Speed Optimizer plugin when Lazy Load Media is enabled.","user_interaction":"not_required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Wordfence","cpe":[],"cvss":{"score":6.4,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"The Speed Optimizer – The All-In-One Performance-Boosting Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Image Tag Attributes in all versions up to, and including, 7.8.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is only exploitable when the site administrator has enabled the Lazy Load Media option in the plugin settings.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Speed Optimizer \u003c= 7.8.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Image Tag Attributes","id":"CVE-2026-15421","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2026"},"n_packages":0,"n_references":9,"next":{"headline":"SCTP needs to better-check INIT ACK chunk parameters","id":"CVE-2026-15422"},"packages":[],"prev":{"headline":"Path traversal in Nexter Blocks – Gutenberg Blocks, Page Builder \u0026 AI Website Builder","id":"CVE-2026-15420"},"products":["Speed Optimizer – The All-In-One Performance-Boosting Plugin"],"published":"2026-08-19","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-20","vendors":["siteground"]},"summary":"Authenticated contributors can inject arbitrary scripts via image tags in Speed Optimizer plugin when Lazy Load Media is enabled.","url":"https://insights.sbomify.com/CVE-2026-15421/"}