CVE-2026-1978 is a vulnerability identified in the kalyan02 NanoCMS content management system, specifically affecting versions 0.1 through 0.4. The issue arises from improper handling of direct requests to the file /data/pagesdata.txt, which is part of the User Information Handler component. This flaw allows an attacker to remotely manipulate requests to this file without requiring authentication or user interaction, potentially leading to unauthorized access to user information or other sensitive data stored or referenced therein. The vulnerability is classified under a medium severity with a CVSS 4.0 base score of 6.9, reflecting its network attack vector, low attack complexity, and no required privileges or user interaction. The impact primarily concerns confidentiality, as the vulnerability does not affect integrity or availability. The exploit code has been publicly disclosed, increasing the risk of exploitation, although no active exploitation in the wild has been reported to date. The vulnerability does not have an official patch available, but the advisory recommends changing configuration settings to mitigate the risk. This suggests that configuration hardening or disabling access to the vulnerable component/file may reduce exposure. The lack of CWE classification and patch links indicates that this is a relatively new or less documented vulnerability, requiring organizations to proactively assess their NanoCMS deployments and apply recommended mitigations.

For European organizations, the vulnerability poses a risk of unauthorized data disclosure through remote exploitation of the NanoCMS User Information Handler. Organizations using affected versions of NanoCMS may face confidentiality breaches, potentially exposing sensitive user or site data stored in or referenced by /data/pagesdata.txt. This could lead to reputational damage, regulatory non-compliance (e.g., GDPR violations), and potential downstream attacks leveraging exposed information. The vulnerability does not directly impact system integrity or availability, so operational disruption is less likely. However, given the public availability of exploit code, the risk of opportunistic attacks increases, especially for organizations with internet-facing NanoCMS instances. The medium severity rating indicates a moderate threat level, but the ease of exploitation without authentication or user interaction elevates the urgency for mitigation. European sectors with high reliance on CMS platforms for public-facing websites, such as government, education, and SMEs, may be particularly vulnerable if using NanoCMS. Failure to address this vulnerability could result in data leaks and subsequent compliance and legal challenges under European data protection laws.

1. Immediately audit all NanoCMS installations to identify versions 0.1 through 0.4 in use. 2. Restrict or disable remote access to the /data/pagesdata.txt file via web server configuration (e.g., using .htaccess rules or web server access control lists) to prevent direct requests. 3. Harden NanoCMS configuration settings as recommended by the vendor or community, focusing on user information handling components. 4. Monitor web server logs for unusual or unauthorized access attempts targeting /data/pagesdata.txt or related endpoints. 5. If possible, upgrade to a newer, unaffected version of NanoCMS once available or consider migrating to alternative CMS platforms with active security support. 6. Implement web application firewalls (WAFs) with custom rules to block suspicious requests targeting the vulnerable component. 7. Conduct regular vulnerability scans and penetration tests focusing on CMS components to detect similar issues proactively. 8. Educate IT and security teams about this vulnerability and the importance of securing CMS components against direct request attacks. 9. Prepare incident response plans to quickly address any exploitation attempts involving this vulnerability. 10. Engage with the NanoCMS vendor or community for updates on patches or official guidance.