{"basis":"claimed","id":"CVE-2025-53691","name":"Sitecore Experience Remote Code Execution through Insecure Deserialization","vendorProject":"Sitecore","product":"Experience Manager (XM)","publishedAt":"2025-09-03","cvss":{"score":8.8,"severity":"HIGH","version":"3.1"},"exploited":null,"epss":{"score":0.01636,"percentile":0.76322,"date":"2026-11-02"},"coverage":{"cloudflare":{"status":"blocks","firstOn":"2025-09-04","daysToRule":1},"aws":{"status":"none","firstOn":null,"daysToRule":null},"azure":{"status":"none","firstOn":null,"daysToRule":null},"google":{"status":"none","firstOn":null,"daysToRule":null},"fastly":{"status":"no_history","firstOn":null,"daysToRule":null},"f5":{"status":"rule","firstOn":"2025-12-03","daysToRule":91},"akamai":{"status":"no_source","firstOn":null,"daysToRule":null},"crs":{"status":"none","firstOn":null,"daysToRule":null}},"title":"Sitecore Experience Remote Code Execution through Insecure Deserialization","description":"Deserialization of Untrusted Data vulnerability in Sitecore Experience Manager (XM), Sitecore Experience Platform (XP) allows Remote Code Execution (RCE).This issue affects Experience Manager (XM): from 9.0 through 9.3, from 10.0 through 10.4; Experience Platform (XP): from 9.0 through 9.3, from 10.0 through 10.4.","cwes":["CWE-502"],"vendors":[{"vendor":"cloudflare","status":"blocks","basis":"claimed","firstOn":"2025-09-04","firstIsNew":true,"daysToRule":1,"daysAtMost":null,"freePlan":false,"claims":[{"id":"8b162be5fed06fb6f8f4bfa010593f7e2aca8241b21146d3811d2dda37f3db15","cve_id":"CVE-2025-53691","vendor":"cloudflare","product":"Cloudflare Managed Ruleset","rule_id":"588edc74df1f4609b3c2f7ef0ee2c15e","rule_name":"Sitecore - Remote Code Execution - CVE:CVE-2025-53691","change":"new","default_action":"Block","published_on":"2025-09-04","source_url":"https://developers.cloudflare.com/changelog/post/2025-09-04-emergency-waf-release/","source_title":"WAF Release - 2025-09-04 - Emergency","excerpt":"Sitecore - Remote Code Execution - CVE:CVE-2025-53691. Previous action: N/A. New action: Block. This is a new detection","first_seen_at":"2026-11-02T21:00:16.135Z"}]},{"vendor":"aws","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"azure","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"google","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"fastly","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"f5","status":"rule","basis":"claimed","firstOn":"2025-12-03","firstIsNew":true,"daysToRule":91,"daysAtMost":null,"freePlan":false,"claims":[{"id":"6d3d7e39b6e017077cde5707e0b5447ab68f921b05ca756b30718a5dabfef15a","cve_id":"CVE-2025-53691","vendor":"f5","product":"Attack signatures","rule_id":"200204029","rule_name":"Sitecore Unsafe Deserialization (2)","change":"new","default_action":null,"published_on":"2025-12-03","source_url":"https://docs.cloud.f5.com/docs-v2/platform/changelogs/security-details-changelog","source_title":"F5 Distributed Cloud attack signatures changelog","excerpt":"Added: signature 200204029 \"Sitecore Unsafe Deserialization (2)\" (Server Side Code Injection, risk High), systems: Microsoft Windows, IIS, ASP, ASP.NET. References: CVE-2025-53691.","first_seen_at":"2026-11-02T21:00:25.505Z"}]},{"vendor":"akamai","status":"no_source","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"crs","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]}],"updatedAt":"2026-11-03T18:25:15.447Z","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total"},"kevAction":null,"kevNotes":null,"references":[{"url":"https://labs.watchtowr.com/cache-me-if-you-can-sitecore-experience-platform-cache-poisoning-to-rce/","name":null,"tags":[]},{"url":"https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB1003667","name":null,"tags":[]}],"affected":[{"vendor":"Sitecore","product":"Experience Manager (XM)","affected":["9.0 through 9.3","10.0 through 10.4"],"fixed":[]},{"vendor":"Sitecore","product":"Experience Platform (XP)","affected":["9.0 through 9.3","10.0 through 10.4"],"fixed":[]}],"briefing":{"status":{"id":"monitor","label":"Monitor"},"why":"Exploitation in the wild is not established by CISA KEV.","who":"Teams running Sitecore Experience Manager (XM) (9.0 through 9.3; 10.0 through 10.4) and Sitecore Experience Platform (XP) (9.0 through 9.3; 10.0 through 10.4). Prioritise internet-facing instances.","what_to_do":[{"text":"Apply the vendor's fix; the advisory lists the affected and fixed versions."},{"text":"Keep a WAF rule in place while you patch: Cloudflare blocks it by default; F5 ships a rule you may need to switch on. A WAF rule reduces exposure; it does not replace the patch.","href":"#edge","linkText":"Edge coverage"},{"text":"Check which WAF sits in front of your site and whether it covers this CVE.","href":"#check","linkText":"Check your domain"}],"evidence":[{"heading":"CVE record","text":"CVSS 3.1 8.8 (high). Weakness: CWE-502.","links":[{"label":"CVE-2025-53691","href":"https://www.cve.org/CVERecord?id=CVE-2025-53691"},{"label":"NVD","href":"https://nvd.nist.gov/vuln/detail/CVE-2025-53691"}]},{"heading":"Exploit evidence","text":"No public exploit code found in Exploit-DB, Metasploit, nuclei-templates or GitHub. That does not mean none exists.","links":[]},{"heading":"CISA KEV","text":"Not in the KEV catalog (catalog 2026.11.03, checked 2026-11-04). Absence from KEV is not evidence that it cannot be exploited.","links":[{"label":"CISA KEV catalog","href":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog"}]},{"heading":"EPSS","text":"1.64% probability of exploitation activity in the next 30 days, higher than 76% of CVEs (2026-11-02).","links":[{"label":"FIRST EPSS","href":"https://api.first.org/data/v1/epss?cve=CVE-2025-53691"}]},{"heading":"WAF vendor statements","text":"Cloudflare and F5 name it in a changelog. Quotes and dates below.","links":[{"label":"Vendor statements","href":"#evidence"}]}],"agent_prompt":"Assess whether the infrastructure available to you is affected by CVE-2025-53691 (Sitecore Experience Remote Code Execution through Insecure Deserialization). Perform a read-only assessment within your authorized access. Do not send exploit traffic, scan third-party systems, change configuration or restart services.\n\n1. Verify the CVE record at https://www.cve.org/CVERecord?id=CVE-2025-53691 and the vendor advisory. Establish affected and fixed versions, including vendor backports. The record lists: Sitecore Experience Manager (XM): affected 9.0 through 9.3; 10.0 through 10.4 | Sitecore Experience Platform (XP): affected 9.0 through 9.3; 10.0 through 10.4. Cite sources and retrieval dates; flag anything you cannot verify.\n2. Inventory deployments of Sitecore Experience Manager (XM): asset, environment, owner where known, installed version or build, and how you confirmed it (package metadata, a version endpoint, image tags). An image tag alone does not prove the running version.\n3. Identify which deployments are reachable from the internet or untrusted networks, and through which paths (direct origin, load balancer, CDN or WAF).\n4. Assess compensating controls separately from patch status. Current edge WAF coverage for this CVE: Cloudflare: rule blocks by default; F5: rule exists, check whether it is enabled. Live data: https://cve.vigilbase.com/api/v1/cves/CVE-2025-53691. Check whether the rule is enabled and in block mode on each path, and whether any path bypasses the WAF. A WAF rule is not a patch.\n5. Check logs on exposed instances for requests matching the public exploit, if your access allows.\n\nReturn a short summary and a table: asset | version/build | assessment (affected, fixed, not applicable, unknown) | exposure | compensating control | evidence | next action. List what you could not assess and the access needed to resolve it. Do not infer absence of compromise from patch status or a lack of alerts.\n\nRemediation guidance: Apply the vendor's fix; the advisory lists the affected and fixed versions. Keep a WAF rule in place while you patch: Cloudflare blocks it by default; F5 ships a rule you may need to switch on. A WAF rule reduces exposure; it does not replace the patch.\nMore: https://cve.vigilbase.com/cve/CVE-2025-53691"},"measured":[],"sightings":null,"social":{"total":0,"first_seen":null,"daily":[{"day":"2026-10-22","posts":0},{"day":"2026-10-23","posts":0},{"day":"2026-10-24","posts":0},{"day":"2026-10-25","posts":0},{"day":"2026-10-26","posts":0},{"day":"2026-10-27","posts":0},{"day":"2026-10-28","posts":0},{"day":"2026-10-29","posts":0},{"day":"2026-10-30","posts":0},{"day":"2026-10-31","posts":0},{"day":"2026-11-01","posts":0},{"day":"2026-11-02","posts":0},{"day":"2026-11-03","posts":0},{"day":"2026-11-04","posts":0}],"top_posts":[],"exploit_repositories":[]}}