CVE Intelligence
High Insecure deserialization exploit reference

CVE-2025-53691 — Sitecore Experience Remote Code Execution through Insecure Deserialization

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.

Published Sep 3, 2025 · Updated Oct 18, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Wiz

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
  • EPSS 1.6% (30-day exploitation probability)+11
  • Technical severity (high)+6
  • CISA SSVC: exploitation "poc"+5

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
1.64%
ahead of 76% of scored CVEs · Oct 19, 2026
Affects
Sitecore
Experience Commerce and 5 more
CVSS base
8.8
High · 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
Proof of concept
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

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

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

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 (Sitecore Experience Commerce, Sitecore Experience Manager, Sitecore Experience Manager (XM)…).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (insecure deserialization), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Sitecore Experience Commerce ≥ 9.0 and ≤ 10.4 Vulnerable NIST National Vulnerability Database
Sitecore Experience Manager ≥ 9.0 and ≤ 10.4 Vulnerable NIST National Vulnerability Database
Sitecore Experience Manager (XM) ≥ 9.0 and ≤ 9.3≥ 10.0 and ≤ 10.4 Vulnerable CVE Program (cve.org) e CISA ADP
Sitecore Experience Platform ≥ 9.0 and < 10.4version 10.4 Vulnerable NIST National Vulnerability Database
Sitecore Experience Platform (XP) ≥ 9.0 and ≤ 9.3≥ 10.0 and ≤ 10.4 Vulnerable CVE Program (cve.org) e CISA ADP
Sitecore Managed Cloud versions not specified by the source Vulnerable NIST National Vulnerability Database

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 3.1 High 2.8 5.9 9947ef80-c5d5-474a-bbab-97341a59000e via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
8.8 CVSS 3.1 High — — Wiz via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 9947ef80-c5d5-474a-bbab-97341a59000e)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-502 · Deserialization of Untrusted Data

Other CVEs with this weakness →

EPSS over time FIRST

Oct 18, 2026 → Oct 19, 2026 · 2 reading(s) · max 1.64%

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).
  • Monitor serialized objects in requests and unexpected processes spawned by the runtime.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · sitecore/experience manager (xm), sitecore/experience platform (xp)
    Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 18, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 18, 2026
  • Affected products added · sitecore/experience commerce, sitecore/experience manager, sitecore/experience platform, sitecore/managed cloud
    Oct 18, 2026 · NIST National Vulnerability Database
  • CVSS changed · 8.8
    Oct 18, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 18, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 18, 2026 · Alertas do Telegram
  • 2025
  • CVE published
    Sep 3, 2025 · Wiz

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 18, 2026 – Oct 18, 2026
  • 1× Official description updated · Oct 18, 2026 – Oct 18, 2026

References

5 on the record

Elsewhere on this site

Sitecore
every CVE for this vendor
Insecure deserialization
same class
CWE-502
other pages naming this weakness

Related CVEs (same products)

  • CVE-2025-53692 Sitecore Experience Platform Cross-Site Scripting Vulnerability Sep 21, 2025
  • CVE-2025-53690 Sitecore Multiple Products Deserialization of Untrusted Data Vulnerability KEV Sep 3, 2025
  • CVE-2025-53693 HTML Cache Poisoning through Unsafe Reflections Sep 3, 2025
  • CVE-2025-53694 Information Disclosure in ItemServices API Sep 3, 2025
  • CVE-2021-42237 Sitecore XP Remote Command Execution Vulnerability KEV Nov 5, 2021
  • CVE-2019-9874 Sitecore CMS and Experience Platform (XP) Deserialization Vulnerability KEV May 31, 2019

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 fixed version, patch or mitigation documented.
  • 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-2025-53691 is "Sitecore Experience Remote Code Execution through Insecure Deserialization", rated High. It affects Experience Commerce (Sitecore); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 1.64% estimates the probability of exploitation in 30 days; neither replaces your asset context. 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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