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Full vulnerability report · 2026
CVE-2026-24775High confidence

OpenProject has Forced Actions, Content Spoofing, and Persistent DoS via ID Manipulation in OpenProject Blocknote Editor Extension

opf · openproject

Official source article: GitHub GHSA-35C6-X276-2PVC ↗. Check the applicable product and release in the original source.

6.3MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.13% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs opf openproject and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-4878

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

OpenProject is an open-source, web-based project management software. In the new editor for collaborative documents based on BlockNote, OpenProject maintainers added a custom extension in OpenProject version 17.0.0 that allows to mention OpenProject work packages in the document. To show work package details, the editor loads details about the work package via the OpenProject API. For this API call, the extension to the BlockNote editor did not properly validate the given work package ID to be only a number. This allowed an attacker to generate a document with relative links that upon opening could make arbitrary `GET` requests to any URL within the OpenProject instance. This issue was patched in version version 0.0.22 of op-blocknote-extensions, which was shipped with OpenProject 17.0.2. If users cannot update immediately to version 17.0.2 of OpenProject, administrators can disable collaborative document editing in Settings -> Documents -> Real time collaboration -> Disable.

What

OpenProject is an open-source, web-based project management software. In the new editor for collaborative documents based on BlockNote, OpenProject maintainers added a custom extension in OpenProject version 17.0.0 that allows to mention OpenProject work packages in the document. To show work package details, the editor loads details about the work package via the OpenProject API. For this API call, the extension to the BlockNote editor did not properly validate the given work package ID to be only a number. This allowed an attacker to generate a document with relative links that upon opening could make arbitrary `GET` requests to any URL within the OpenProject instance. This issue was patched in version version 0.0.22 of op-blocknote-extensions, which was shipped with OpenProject 17.0.2. If users cannot update immediately to version 17.0.2 of OpenProject, administrators can disable collaborative document editing in Settings -> Documents -> Real time collaboration -> Disable.

Why

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

OpenProject is an open-source, web-based project management software. In the new editor for collaborative documents based on BlockNote, OpenProject maintainers added a custom extension in OpenProject version 17.0.0 that allows to mention OpenProject work packages in the document. To show work package details, the editor loads details about the work package via the OpenProject API. For this API call, the extension to the BlockNote editor did not properly validate the given work package ID to be only a number. This allowed an attacker to generate a document with relative links that upon opening could make arbitrary `GET` requests to any URL within the OpenProject instance. This issue was patched in version version 0.0.22 of op-blocknote-extensions, which was shipped with OpenProject 17.0.2. If users cannot update immediately to version 17.0.2 of OpenProject, administrators can disable collaborative document editing in Settings -> Documents -> Real time collaboration -> Disable.

Why

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Insufficient Verification of Data Authenticity → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-345 ↗

CWE-345: Insufficient Verification of Data Authenticity. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.ILowIntegrity impact: A successful attack can cause a limited loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-345
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20260204Security Bulletin 04 Feb 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 04 Feb 2026, published on 4 February 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-003761OpenProjectにおけるデータの信頼性についての不十分な検証に関する脆弱性

OpenProjectはオープンソースのウェブベースのプロジェクト管理ソフトウェアです。BlockNoteに基づく新しい共同編集用エディタにおいて、OpenProjectのメンテナはバージョン17.0.0で、ドキュメント内でOpenProjectの作業パッケージをメンションできるカスタム拡張機能を追加しました。作業パッケージの詳細を表示するために、エディタはOpenProject APIを通じて作業パッケージの詳細を読み込みます。このAPI呼び出しにおいて、BlockNoteエディタの拡張機能は与えられた作業パッケージIDが数値のみであるかを適切に検証していませんでした。これにより、攻撃者は相対リンクを含むドキュメントを作成し、開いたときにOpenProjectインスタンス内の任意のURLへ任意のGETリクエストを送信できる可能性がありました。この問題はop-blocknote-extensionsのバージョン0.0.22で修正されています。このバージョンはOpenProject 17.0.2に同梱されています。ユーザーが直ちにOpenProject 17.0.2に更新できない場合、管理者は設定 - ドキュメント - リアルタイムコラボレーション - 無効化の順に操作して共同編集を無効にできます。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
openproject: >= 17.0.0, < 17.0.2
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 28 Jan 2026 · Last source change 28 Jan 2026, 18:30 UTC · CWE-345 · Insufficient Verification of Data Authenticity

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-4878
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-24775 · cve.blacktree.nl