Cyber Resilience

CVE-2023-22515

Atlassian Confluence Data Center 8.0.0 – 8.3.3

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRansomware-linked
Published
04 October 2023
Modified
25 March 2026
KEV Added
05 October 2023
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.99 99.9th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2023-22515 is a critical-severity Improper Input Validation (CWE-20) vulnerability in Atlassian Confluence Data Center. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-22515 is a critical unauthenticated vulnerability affecting publicly accessible Atlassian Confluence Data Center and Server instances. It enables external attackers to create unauthorized administrator accounts and subsequently access the Confluence instance. Atlassian Cloud sites hosted under atlassian.net domains are not impacted. The flaw carries a CVSS 3.1 score of 9.8 and is associated with improper input validation weaknesses.

External attackers with no prior credentials can target internet-facing Confluence Server or Data Center deployments to provision admin accounts and achieve full control over the instance, including the ability to execute arbitrary code.

Public exploit code for unauthenticated remote code execution has been posted to Packet Storm, and Atlassian has published mitigation guidance and a dedicated knowledge-base article at confluence.atlassian.com along with a Jira tracking entry. The EPSS score has reached a peak of 0.9739 with a current value of 0.9433, indicating sustained and widespread exploitation interest following disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Atlassian has been made aware of an issue reported by a handful of customers where external attackers may have exploited a previously unknown vulnerability in publicly accessible Confluence Data Center and Server instances to create unauthorized Confluence administrator accounts and…

more

access Confluence instances. Atlassian Cloud sites are not affected by this vulnerability. If your Confluence site is accessed via an atlassian.net domain, it is hosted by Atlassian and is not vulnerable to this issue.

CWE(s)
KEV Date Added
05 October 2023

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-22518Same product: Atlassian Confluence Data Centerboth on KEV
CVE-2022-26134Same product: Atlassian Confluence Data Centerboth on KEV
CVE-2021-26084Same product: Atlassian Confluence Data Centerboth on KEV
CVE-2021-26085Same product: Atlassian Confluence Data Centerboth on KEV
CVE-2023-22527Same product: Atlassian Confluence Data Centerboth on KEV
CVE-2022-26138Same product: Atlassian Confluence Data Centerboth on KEV
CVE-2023-22526Same product: Atlassian Confluence Data Center
CVE-2024-21674Same product: Atlassian Confluence Data Center
CVE-2019-3398Same product: Atlassian Confluence Serverboth on KEV
CVE-2024-21673Same product: Atlassian Confluence Data Center

Affected Assets

atlassian
confluence data center
8.0.0 — 8.3.3 · 8.4.0 — 8.4.3 · 8.5.0 — 8.5.2
atlassian
confluence server
8.0.0 — 8.3.3 · 8.4.0 — 8.4.3 · 8.5.0 — 8.5.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require and enforce input validation during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

prevents

Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.

prevents

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

prevents

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

none

Regular automated validation of system software and data content, combined with scanning of all inbound files, enforces input validation at the boundary before untrusted content is processed.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (1 rule)
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-20

References