Security readout for executives and security teams
Plain-English summary
CVE-2026-1691 affects bolo-solo versions 2.6.0 through 2.6.4. A remote authenticated user may trigger unsafe SnakeYAML deserialization through the Markdown import backup service. Public proof-of-concept information is referenced, but CISA KEV is false and the provided sources do not show active exploitation.
Executive priority
Treat as a near-term remediation item for affected bolo-solo deployments, especially externally reachable or shared-admin systems. It is not KEV-listed, but public exploit disclosure and deserialization impact justify prompt validation and access restriction while awaiting or applying vendor guidance.
Technical view
The issue is in src/main/java/org/b3log/solo/bolo/prop/BackupService.java, function importMarkdownsSync, involving SnakeYAML deserialization. The CVSS v2 score is 6.5 with network access, low complexity, and required authentication. Listed CWEs are CWE-20 and CWE-502. VulDB states public exploit disclosure and possible use.
Likely exposure
Exposure is likely limited to organizations running bolo-solo 2.6.0, 2.6.1, 2.6.2, 2.6.3, or 2.6.4 with authenticated access to Markdown import or backup-related functionality. Internet-facing administration or multi-user deployments raise urgency.
Exploitation context
Sources indicate remote exploitation is possible and authentication is required. Public exploit material is referenced by VulDB and GitHub issue links. There is no provided evidence of active exploitation in the wild or KEV listing.
Researcher notes
The provided bundle names affected versions and vulnerable code location, but does not include a confirmed patched version or vendor workaround. Do not assume unauthenticated exposure: the CVSS vector requires authentication. Public exploit disclosure is cited, but active exploitation is not established.
Mitigation direction
- Inventory bolo-solo deployments and identify versions 2.6.0 through 2.6.4.
- Review the GitHub issue and vendor project guidance for an official fix or workaround.
- Restrict access to Markdown import and backup functions to trusted administrators only.
- Avoid exposing administrative bolo-solo interfaces directly to the internet.
- Monitor application logs for unusual authenticated import or backup activity.
Validation and detection
- Confirm the running bolo-solo version on each instance.
- Determine whether importMarkdownsSync-related functionality is reachable by authenticated users.
- Review account access to administrative import and backup capabilities.
- Check vendor issue #325 for remediation status and affected-code discussion.
- Correlate logs for unexpected import attempts by valid accounts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-1691 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (2.0)
- Known Exploited
- No
- Published
Vector: AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:C86.4Primary CVE scoreVulnerability scoring details
Base CVSS 2.0 score
6.5MediumVector: AV:N/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:ND/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- VDB-343485 | bolo-solo SnakeYAML BackupService.java importMarkdownsSync deserializationCVE reference · vdb-entry, technical-description
- VDB-343485 | CTI Indicators (IOB, IOC, IOA)CVE reference · signature, permissions-required
- Submit #741899 | bolo-solo V2.6.4 SnakeYAML deserialization vulnerabilityCVE reference · third-party-advisory
- https://github.com/bolo-blog/bolo-solo/issues/325CVE reference · issue-tracking, exploit
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.