Security readout for executives and security teams
Plain-English summary
CVE-2026-21875 is a critical database injection flaw in ClipBucket v5 channel comments. An unauthenticated remote attacker may be able to manipulate database queries through a comment request, risking data theft, data changes, or service disruption. The advisory states no fix was available at publication.
Executive priority
Treat this as urgent for any public ClipBucket v5 deployment. The vulnerability can affect confidentiality, integrity, and availability, and no fix was named in the source at publication. Reduce exposure while monitoring the vendor advisory for remediation.
Technical view
ClipBucket v5 versions 5.5.2-#187 and below are affected. The vulnerable flow is channel comment submission to /actions/ajax.php, where obj_id reaches user_exists and db count logic without proper validation or sanitization. This is classified as CWE-89 blind SQL injection with CVSS 3.1 score 9.8.
Likely exposure
Exposure is likely for internet-facing ClipBucket v5 sites running version 5.5.2-#187 or earlier with channel comment functionality reachable by unauthenticated users. The source does not identify hosted services, default deployments, or confirmed affected forks beyond MacWarrior clipbucket-v5.
Exploitation context
The CVE record and GitHub advisory describe a network-accessible, low-complexity, unauthenticated issue requiring no user interaction. The provided sources do not state active exploitation, public exploit availability, or inclusion in CISA KEV.
Researcher notes
Evidence is limited to the CVE data and GitHub security advisory. The root cause is unsanitized use of obj_id in database query construction during channel comment handling. Do not assume exploit activity or patch availability beyond the cited sources.
Mitigation direction
- Check the GitHub advisory and vendor project for updated remediation guidance.
- Identify and prioritize all ClipBucket v5 deployments at or below 5.5.2-#187.
- Restrict external access to affected ClipBucket instances where business feasible.
- Limit or disable channel comment functionality if supported by your deployment.
- Increase monitoring for unusual database errors or abnormal comment activity.
Validation and detection
- Inventory ClipBucket v5 version and build number across environments.
- Confirm whether channel comment submission is reachable from untrusted networks.
- Review application logs for suspicious requests to /actions/ajax.php.
- Check database logs for malformed or abnormal queries tied to comment activity.
- Track vendor advisory updates for a fixed version or official workaround.
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-89: Database access and collection lookup
Injection into data stores can inform collection, data access, and exfiltration detection reviews. 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 lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-21875 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/MacWarrior/clipbucket-v5/security/advisories/GHSA-crpv-fmc4-j392CVE reference · x_refsource_CONFIRM
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 Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.