Security readout for executives and security teams
Plain-English summary
BookStack versions before 0.30.4 allowed a page editor to attach a link that could run untrusted JavaScript when another user clicked it. The attacker needs edit rights, but the victim may be any page viewer. Successful abuse could expose sensitive data or alter user-visible content.
Executive priority
Treat this as a high-priority fix for affected BookStack systems, particularly where many users can edit documentation. The vulnerability is not described as actively exploited, but stored content may survive patching and needs review if misuse is suspected.
Technical view
This is a stored cross-site scripting issue in BookStack attached links. It requires a low-privileged user with page edit permission and viewer interaction. CVSS 3.1 is 7.7, with changed scope and high confidentiality and integrity impact. Fixed in BookStack 0.30.4.
Likely exposure
Exposure is limited to BookStack deployments running versions earlier than 0.30.4, especially sites with broad contributor permissions or compromised editor accounts. Public or partner-accessible knowledge bases increase business risk because more viewers may encounter malicious links.
Exploitation context
The source bundle does not show KEV listing or cited evidence of active exploitation. The advisory warns dangerous content may remain in the database after upgrade, so prior misuse cannot be ruled out without local review.
Researcher notes
The strongest evidence is the GitHub advisory, CVE record, release note, and fixing commit. Do not assume broader product impact. The key nuance is persistence: upgrading fixes new injection but may not remove previously stored dangerous links.
Mitigation direction
- Upgrade BookStack to version 0.30.4 or later.
- Restrict page edit permissions to trusted users until upgrade is complete.
- Use the vendor advisory to check for dangerous persisted content.
- Remove or sanitize any suspicious attached links found in the database.
- Review BookStack guidance before changing database content manually.
Validation and detection
- Inventory all BookStack instances and confirm their running versions.
- Verify no production instance remains below version 0.30.4.
- Review roles with page edit permission for least privilege.
- If exploitation is suspected, run the vendor-provided detection query.
- Check page history and audit data for unexpected attached links.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2020-26210 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:H/PR:L/UI:R/S:C/C:H/I:H/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:H/PR:L/UI:R/S:C/C:H/I:H/A:N1.35.8Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.7HighVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/BookStackApp/BookStack/security/advisories/GHSA-7p2j-4h6p-cq3hCVE reference · x_refsource_CONFIRM
- https://github.com/BookStackApp/BookStack/commit/349162ea139556b2d25e09e155cec84e21cc9227CVE reference · x_refsource_MISC
- https://bookstackapp.com/blog/beta-release-v0-30-4/CVE reference · x_refsource_MISC
- https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4CVE 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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.