Security readout for executives and security teams
Plain-English summary
Kanboard installations using LDAP authentication may let unauthenticated attackers query LDAP in unintended ways. The main business risk is exposure of user lists and sensitive account attributes, which can support phishing, password attacks, or account targeting. The issue affects Kanboard versions before 1.2.49 and is fixed in 1.2.49.
Executive priority
Treat this as a timely security maintenance update, especially for LDAP-backed and internet-facing Kanboard systems. It is medium severity because it mainly exposes account information, but that information can enable more damaging follow-on attacks. Upgrade during the next available patch window, sooner for externally accessible systems.
Technical view
CVE-2026-21880 is an LDAP injection in Kanboard’s LDAP authentication mechanism. Versions 1.2.48 and below substitute user input into LDAP search filters without adequate sanitization. The CVSS 3.1 score is 5.3, with network access, low complexity, no privileges, no user interaction, and low confidentiality impact.
Likely exposure
Exposure is limited to Kanboard deployments using LDAP authentication on versions below 1.2.49. Internet-facing login pages increase practical risk because the CVSS vector indicates remote, unauthenticated access. Deployments not using LDAP authentication are less likely to be affected, based on the described vulnerable component.
Exploitation context
The sources describe user enumeration, disclosure of LDAP user attributes, and targeted account attacks. CISA KEV status is false in the provided bundle, and no cited source states active exploitation. The issue is not described as enabling code execution, privilege escalation, or service outage.
Researcher notes
The advisory attributes the flaw to unsafe substitution of user-controlled input into LDAP search filters. The supplied fix reference is commit dd374079f7c2d1dab74c1680960e684ff8668586, and the release reference is v1.2.49. Evidence does not establish public exploitation or impact beyond information disclosure and enumeration.
Mitigation direction
- Upgrade Kanboard to version 1.2.49 or later.
- Prioritize internet-facing Kanboard instances using LDAP authentication.
- Review vendor advisory and release notes before deployment.
- If immediate upgrade is delayed, monitor authentication endpoints and LDAP query anomalies.
Validation and detection
- Inventory Kanboard versions and identify instances below 1.2.49.
- Confirm whether LDAP authentication is enabled.
- Check whether exposed instances are reachable from the internet.
- Review logs for unusual authentication attempts or LDAP lookup patterns.
- Verify the installed version after upgrade.
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-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. 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-90: 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 lookupCVE-2026-21880 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
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
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:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/kanboard/kanboard/security/advisories/GHSA-v66r-m28r-wmq7CVE reference · x_refsource_CONFIRM
- https://github.com/kanboard/kanboard/commit/dd374079f7c2d1dab74c1680960e684ff8668586CVE reference · x_refsource_MISC
- https://github.com/kanboard/kanboard/releases/tag/v1.2.49CVE reference · x_refsource_MISC
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.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')
Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.