CriticalCISA KEVExploited in the wildPublic exploit

Adobe ColdFusion Deserialization of Untrusted Data RCE

IdentifiersCVE-2023-38203CWE-502· Deserialization of Untrusted Data

CVE-2023-38203 is a critical deserialization of untrusted data vulnerability in Adobe ColdFusion affecting 2018 Update 17 and earlier, 2021 Update 7 and earlier, and 2023 Update 1 and earlier. According to the provided content, successful exploitation can result in arbitrary code execution and does not require user interaction. The supporting material further associates exploitation activity against ColdFusion with WDDX deserialization and JNDI/LDAP-based callback behavior in broader ColdFusion campaigns, but the specific vulnerable function or code path for CVE-2023-38203 is not identified in the provided content. The issue is remotely exploitable against exposed ColdFusion instances and has been observed in active exploitation.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows arbitrary code execution on the vulnerable ColdFusion server. This can enable full compromise of the application instance, deployment of follow-on payloads such as webshells or ransomware tooling, access to sensitive application data, and use of the server as an initial access point into the broader environment. The content indicates the vulnerability has been used by threat actors including Storm-0501 for initial access and has been added to CISA's KEV catalog as actively exploited.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure of ColdFusion servers by restricting public access to ColdFusion administrative and CFIDE-related endpoints, limiting internet exposure to only required application interfaces, and monitoring for exploitation indicators such as suspicious crafted requests, deserialization activity, JNDI/LDAP callback attempts, unexpected outbound connections, and webshell deployment. Threat hunting on internet-facing ColdFusion systems is warranted because the vulnerability is known to be actively exploited.

Remediation

Patch, then assume compromise.

Apply Adobe's security updates referenced in APSB23-41 for ColdFusion. The provided content states that Adobe released patches for affected ColdFusion versions and that multiple patches were issued to resolve this vulnerability. Organizations should upgrade ColdFusion 2018, 2021, and 2023 installations to vendor-fixed versions later than 2018u17, 2021u7, and 2023u1 respectively, following Adobe's advisory guidance.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

AdobeColdfusionapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

11 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

11 SOURCESView more in app

shroudcloudNews

Apr 14, 2026

Embargo - ShroudCloud

An Adobe ColdFusion vulnerability cited as one of the known N-days exploited by Storm-0501/Embargo for initial access.

secpod blogNews

Jan 6, 2026

Mass Exploitation Campaign Targeting Adobe ColdFusion Servers Detected During Christmas Holiday

A remote code execution vulnerability in Adobe ColdFusion, allowing attackers to execute arbitrary code pre-authentication.

securityaffairsNews

Jan 3, 2026

Thousands of ColdFusion exploit attempts spotted during Christmas holiday

A remote code execution vulnerability in Adobe ColdFusion, targeted in a large-scale exploitation campaign.

securityaffairsNews

Jan 3, 2026

Thousands of ColdFusion exploit attempts spotted during Christmas holiday

A remote code execution vulnerability in Adobe ColdFusion, targeted in a large-scale exploitation campaign.

+7 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence3

Every observed campaign linking this CVE to a named adversary.

Associated malware1

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2023-38203

NVD

nvd.nist.gov/vuln/detail/CVE-2023-38203

MITRE CWE · CWE-502

Deserialization of Untrusted Data

Patch

helpx.adobe.com/security/products/coldfusion/apsb23-41.html

Third Party Advisory

cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-38203