CVE-2026-1691
Published: 30 January 2026
Summary
CVE-2026-1691 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Adlered Bolo-Solo. Its CVSS base score is 6.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 14.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
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.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Directly implements checks on information inputs to reject invalid data before processing.
Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.
Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.
Integrity verification of serialized information can detect tampering before deserialization occurs.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Unsafe deserialization in a public-facing Java web application (SnakeYAML) directly enables remote exploitation of the server for limited C/I/A impact.
NVD Description
A vulnerability has been found in bolo-solo up to 2.6.4. This impacts the function importMarkdownsSync of the file src/main/java/org/b3log/solo/bolo/prop/BackupService.java of the component SnakeYAML. Such manipulation leads to deserialization. The attack may be launched remotely. The exploit has been disclosed to…
more
the public and may be used.
Deeper analysisAI
CVE-2026-1691, published on 2026-01-30, is a deserialization vulnerability (CWE-20, CWE-502) affecting bolo-solo versions up to 2.6.4. The issue resides in the importMarkdownsSync function within the file src/main/java/org/b3log/solo/bolo/prop/BackupService.java, which relies on the SnakeYAML component. It has a CVSS v3.1 base score of 6.3 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L).
A remote attacker with low privileges can exploit this vulnerability by manipulating inputs to the affected function, triggering unsafe deserialization. Successful exploitation allows limited impacts on confidentiality, integrity, and availability, with no user interaction required and low attack complexity.
Advisories and related discussions, including the initial report, are documented in GitHub issues at https://github.com/bolo-blog/bolo-solo/issues/325 and https://github.com/bolo-blog/bolo-solo/issues/325#issue-3828755519, as well as VulDB entries such as https://vuldb.com/?ctiid.343485, https://vuldb.com/?id.343485, and https://vuldb.com/?submit.741899.
The exploit has been publicly disclosed and may be used by attackers.
Details
- CWE(s)