How do you patch or mitigate CVE-2023-22527 (Atlassian Confluence Data Center and Server Template Injection)?

By NHI Mgmt Group Editorial Team Updated October 19, 2026 Domain: Cyber Security

CISA's required action for CVE-2023-22527 is to apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. In practice, find every instance of Atlassian Confluence Data Center and Server in your estate, apply the vendor security update or documented mitigation, and if no fix can be applied, remove internet exposure or take the product out of service.

What patching CVE-2023-22527 should look like in practice

For this Confluence template injection issue, the first job is to confirm where Atlassian Confluence Data Center and Server is actually deployed and whether each instance is still reachable in a way that matters. Then apply Atlassian’s security update or documented mitigation exactly as the vendor specifies, because the CISA action is mitigation per vendor instructions or discontinuation when mitigation is not available.

In practical terms, that means treating every Confluence instance as an asset that must be found, version-checked, and dispositioned. If the environment is still exposed to the internet, reduce exposure immediately while you work the fix, because template injection becomes far more dangerous when attackers can reach it directly. The safest response is the one that removes the vulnerable service from attack reach, not the one that simply assumes low traffic means low risk.

How to handle systems you cannot patch right away

If patching is delayed, the fallback is not to leave the product in place and hope for the best. Put compensating controls around the instance, such as removing public access, restricting access to trusted networks, and tightening monitoring around the application and its hosting layer. Use the vendor advisory and the CISA Known Exploited Vulnerabilities Catalog to confirm the remediation expectation and the urgency attached to it.

Template injection is especially unforgiving because it can turn a web request into server-side execution paths or data exposure paths depending on how the product processes untrusted input. If business constraints force you to delay remediation, the decision is not just “patch later”, it is “accept a narrower trust boundary now” by constraining who can reach the service and what the service can reach in turn.

Where the product is too old to remediate safely, discontinuing use is the correct control outcome. That may sound drastic, but for a widely reachable collaboration platform the business impact of taking the service offline is often smaller than the downstream impact of a compromise that exposes documents, sessions, integrations, or adjacent systems.

What to check after mitigation or patching

Once remediation is applied, do not stop at confirming the update installed. Validate whether the instance was exposed before the fix, whether suspicious requests or file changes occurred, and whether any Confluence content, plugins, integrations, or authentication-related material was touched during the exposure window. The question is not only “is it patched now?”, but also “was it already used before we closed the door?”.

That follow-up matters because exploited application flaws often leave weak signals rather than obvious alarms. Review web logs, application logs, reverse proxy logs, and host telemetry for unusual template-related requests, unexpected administrative activity, and signs that attackers used the instance as an entry point to other internal resources. If you find evidence of compromise, widen the investigation beyond Confluence itself.

Where the service hosted sensitive content or supported single sign-on workflows, consider whether session material, stored secrets, or service integrations could have been exposed indirectly and rotate them if the investigation supports that conclusion. A patch closes the vulnerability, but it does not automatically undo what an attacker may already have obtained.

Risk and Threat Considerations

Template injection in a collaboration platform is high risk because it can affect both content integrity and server-side trust. When an attacker can submit or influence rendered templates, the issue can become a path to data exposure, server-side action, or foothold establishment, especially if the product is internet-facing or connected to sensitive internal systems.

Failure mechanism: Untrusted template input is processed in a way that allows malicious content to escape normal rendering controls, which can expose data or enable server-side abuse before defenders notice the abuse pattern.

Impact: The likely outcomes are unauthorized access, content compromise, deeper internal reconnaissance, and a larger incident if Confluence is trusted by other applications or administrators.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

OWASP ASVS, CIS Controls v8 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
OWASP ASVS	V15 — Secure Coding and Architecture	Template injection is an application-layer flaw requiring secure handling of untrusted input.
	V16 — Security Logging and Error Handling	Post-patch validation depends on logs that can show exploitation or suspicious rendering activity.
Recommendation — Review template rendering paths and harden input handling so untrusted content cannot alter server-side behavior. Ensure application and proxy logs preserve enough detail to investigate exploitation before remediation.
CIS Controls v8	CIS-7 — Continuous Vulnerability Management	This CVE requires rapid identification, prioritization and remediation of exposed Confluence instances.
	CIS-12 — Network Infrastructure Management	Reducing exposure while patching depends on restricting network reachability to the application.
Recommendation — Continuously inventory Confluence instances and track remediation until the vulnerable service is fixed or removed. Restrict Confluence network exposure until the vendor fix or mitigation is fully in place.
NIST SP 800-53 Rev 5	SI-2 — Flaw Remediation	This CVE response centers on applying the vendor fix or approved mitigation to remediate a flaw.
Recommendation — Apply the vendor remediation or approved mitigation as soon as the vulnerability is confirmed.

Practitioner Guidance

What to prioritise: Identify every Confluence Data Center and Server instance first, then separate them into “patched, mitigated, or must be removed” buckets. That keeps the team from focusing on one visible server while missing older or forgotten deployments.

What to verify: Confirm not just that the vendor fix was applied, but that public exposure was removed or reduced while the fix was pending, and that no suspicious activity occurred in the exposure window. If you can only verify one thing, verify whether the instance was reachable by untrusted users before remediation.

Decision rule: If you cannot apply the vendor update or mitigation, remove the service from internet exposure immediately and treat continued operation as an exception that needs explicit business acceptance. If that acceptance cannot be justified, discontinue the product.

Practitioner takeaway: For exploited web application flaws, the real control objective is not merely patching, it is closing the attacker’s reachable path quickly enough to prevent pre-patch abuse and then proving the system was not already used.

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NHIMG Editorial Note
Reviewed and updated by the NHIMG editorial team on October 19, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org