How severe is CVE-2026-5484?

CVE-2026-5484 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-5484 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-5484?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5484 have an EU (EUVD) identifier?

Yes. CVE-2026-5484 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18819.

When was CVE-2026-5484 published?

CVE-2026-5484 was published on 2026-04-03 and last updated on 2026-06-17.

CVE-2026-5484

CVE-2026-5484 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-266.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
CVSS v4: 5.5
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18819
Weakness: CWE-266
Published: 2026-04-03
Last modified: 2026-06-17

Description

A weakness has been identified in BookStackApp BookStack up to 26.03. Affected is the function chapterToMarkdown of the file app/Exports/ExportFormatter.php of the component Chapter Export Handler. Executing a manipulation of the argument pages can lead to improper access controls. It is possible to launch the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 26.03.1 is able to address this issue. This patch is called 8a59895ba063040cc8dafd82e94024c406df3d04. It is advisable to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

Frequently asked questions

What is CVE-2026-5484?: A weakness has been identified in BookStackApp BookStack up to 26.03. Affected is the function chapterToMarkdown of the file app/Exports/ExportFormatter.php of the component Chapter Export Handler. Executing a manipulation of the argument pages can lead to improper access controls. It is possible to launch the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 26.03.1 is able to address this issue. This patch is called 8a59895ba063040cc8dafd82e94024c406df3d04. It is advisable to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
How severe is CVE-2026-5484?: CVE-2026-5484 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-5484 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-5484?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5484 have an EU (EUVD) identifier?: Yes. CVE-2026-5484 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18819.
When was CVE-2026-5484 published?: CVE-2026-5484 was published on 2026-04-03 and last updated on 2026-06-17.

References

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