Security readout for executives and security teams
Plain-English summary
In GLPI before 9.5.3, any valid user could read other users’ planning calendars through CalDAV, including calendars belonging to administrators or groups they did not belong to. This is a confidentiality issue: calendar and planning data may expose sensitive operational details, but the sources do not indicate data modification or service disruption.
Executive priority
Treat this as a high-priority confidentiality fix for affected GLPI deployments. It does not appear to enable takeover or disruption, but it can expose sensitive IT planning data to any authenticated user.
Technical view
CVE-2020-26212 is a missing authorization issue in GLPI CalDAV planning access. Authenticated low-privilege users received read-only access to other users’ and groups’ planning calendars. CVSS 3.1 is 7.7: network reachable, low complexity, privileges required, no user interaction, changed scope, high confidentiality impact, no integrity or availability impact.
Likely exposure
Organizations running GLPI versions before 9.5.3 with CalDAV reachable to authenticated users are potentially exposed. Exposure depends on whether GLPI planning calendars and CalDAV access were enabled or reachable in the environment.
Exploitation context
The source bundle does not show KEV listing or active exploitation evidence. The issue is authenticated access control bypass, so risk is higher where many users, contractors, or shared accounts can authenticate to GLPI.
Researcher notes
Primary evidence comes from the CVE record and GLPI GitHub advisory. The vendor states 9.5.3 fixes the issue and identifies removal of caldav.php as a workaround. The bundle does not provide evidence of public exploitation beyond the described authorization flaw.
Mitigation direction
- Upgrade GLPI to version 9.5.3 or later.
- Use vendor advisory and release notes to confirm the fixed build.
- If upgrade is delayed, remove caldav.php to block CalDAV access.
- Review whether CalDAV is needed and limit exposure where possible.
- Check vendor guidance before applying any compensating control.
Validation and detection
- Inventory all GLPI instances and identify versions below 9.5.3.
- Confirm fixed instances report GLPI 9.5.3 or later.
- Verify caldav.php is absent or blocked if using the workaround.
- Audit CalDAV access logs for unexpected authenticated calendar reads.
- Review whether sensitive planning data was exposed before remediation.
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-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-26212 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
- High
- CVSS
- 7.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/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:L/UI:N/S:C/C:H/I:N/A:N3.14Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.7HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/glpi-project/glpi/security/advisories/GHSA-qmw3-87hr-5wgxCVE reference · x_refsource_CONFIRM
- https://github.com/glpi-project/glpi/commit/527280358ec78988ac57e9809d2eb21fcd74caf7CVE reference · x_refsource_MISC
- https://github.com/glpi-project/glpi/releases/tag/9.5.3CVE 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.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.