Security readout for executives and security teams
Plain-English summary
A signed-in, non-admin Etherpad user can be treated as an administrator because the system checks whether an `admin` claim exists, not whether it is true. This can expose, alter, move, or delete pads across the instance without administrator privileges.
Executive priority
Treat this as an urgent upgrade for affected OAuth-enabled instances. A legitimate low-privilege account could compromise the confidentiality and integrity of collaborative content across the service, with potential deletion or disruption. Investigate suspicious non-admin API activity alongside remediation.
Technical view
Etherpad 2.1.0 through versions before 3.1.0 improperly authorizes `/api/2/*` requests in the OAuth authorization-code path. Tokens issued to configured non-admin users contain `admin: false`, but the required-claim check accepts the claim's presence. This is CWE-863 improper authorization and is fixed in 3.1.0.
Likely exposure
Exposure requires an affected Etherpad version, the OAuth authorization-code path, and a configured non-admin user able to obtain a valid signed token. Internet-accessible or broadly accessible instances face greater practical risk because the flaw reaches administrative API functions across the instance.
Exploitation context
The vulnerability is network-accessible, requires low privileges, needs no user interaction, and has a CVSS 3.1 score of 9.9. The supplied record is not in KEV, and the source bundle provides no evidence of active exploitation or a public exploit.
Researcher notes
The authorization boundary fails because claim presence is confused with claim value. The provider deliberately issues `admin: false`, making affected non-admin tokens relevant. The referenced fix changes this behavior; the supplied evidence does not establish active exploitation or provide confirmed indicators of compromise.
Mitigation direction
- Upgrade affected Etherpad deployments to version 3.1.0, which contains the fix.
- Review the vendor advisory and release notes for deployment-specific upgrade guidance.
- Prioritize instances exposing OAuth and `/api/2/*` access to untrusted or numerous users.
Validation and detection
- Inventory Etherpad versions and identify deployments from 2.1.0 through versions before 3.1.0.
- Determine whether the OAuth authorization-code path and configured non-admin users are present.
- After upgrading, verify tokens with `admin: false` cannot invoke administrator-only API functions.
- Review `/api/2/*` logs for unexpected administrative calls associated with non-admin identities.
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-863: 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-2026-55089 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
- 9.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
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.
SSVC decision data
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:H/A:L3.16GitHub_MVulnerability scoring details
Base CVSS 3.1 score
9.9CriticalVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/ether/etherpad/security/advisories/GHSA-qfmh-fph3-mw8qCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/ether/etherpad/pull/7784CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/ether/etherpad/commit/8c6104c5d5daf41f0d454acc04d42dffa0e0d996CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/ether/etherpad/releases/tag/v3.1.0CVE reference, GitHub_M · 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.
Incorrect Authorization
Incorrect Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.