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Vulnerability details: VCID-12ay-hyhq-c3a4
Vulnerability ID VCID-12ay-hyhq-c3a4
Aliases CVE-2023-51447
GHSA-9w99-78rj-hmxq
Summary Decidim is a participatory democracy framework. Starting in version 0.27.0 and prior to versions 0.27.5 and 0.28.0, the dynamic file upload feature is subject to potential cross-site scripting attacks in case the attacker manages to modify the file names of the records being uploaded to the server. This appears in sections where the user controls the file upload dialogs themselves and has the technical knowledge to change the file names through the dynamic upload endpoint. Therefore I believe it would require the attacker to control the whole session of the particular user but in any case, this needs to be fixed. Successful exploit of this vulnerability would require the user to have successfully uploaded a file blob to the server with a malicious file name and then have the possibility to direct the other user to the edit page of the record where the attachment is attached. The users are able to craft the direct upload requests themselves controlling the file name that gets stored to the database. The attacker is able to change the filename e.g. to `<svg onload=alert('XSS')>` if they know how to craft these requests themselves. And then enter the returned blob ID to the form inputs manually by modifying the edit page source. Versions 0.27.5 and 0.28.0 contain a patch for this issue. As a workaround, disable dynamic uploads for the instance, e.g. from proposals.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (3)
System Score Found at
epss 0.00487 https://api.first.org/data/v1/epss?cve=CVE-2023-51447
cvssv3.1_qr MODERATE https://github.com/advisories/GHSA-9w99-78rj-hmxq
cvssv3.1 6.3 https://github.com/decidim/decidim
generic_textual MODERATE https://github.com/decidim/decidim
cvssv3.1 6.3 https://github.com/decidim/decidim/commit/aaf72787cf18beeeb6a771c1f7cbb7654b073423
generic_textual MODERATE https://github.com/decidim/decidim/commit/aaf72787cf18beeeb6a771c1f7cbb7654b073423
ssvc Track https://github.com/decidim/decidim/commit/aaf72787cf18beeeb6a771c1f7cbb7654b073423
cvssv3.1 6.3 https://github.com/decidim/decidim/pull/11612
generic_textual MODERATE https://github.com/decidim/decidim/pull/11612
ssvc Track https://github.com/decidim/decidim/pull/11612
cvssv3.1 6.3 https://github.com/decidim/decidim/releases/tag/v0.27.5
generic_textual MODERATE https://github.com/decidim/decidim/releases/tag/v0.27.5
ssvc Track https://github.com/decidim/decidim/releases/tag/v0.27.5
cvssv3.1 6.3 https://github.com/decidim/decidim/releases/tag/v0.28.0
generic_textual MODERATE https://github.com/decidim/decidim/releases/tag/v0.28.0
ssvc Track https://github.com/decidim/decidim/releases/tag/v0.28.0
cvssv3 6.3 https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
cvssv3.1 6.3 https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
cvssv3.1_qr MODERATE https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
generic_textual MODERATE https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
ssvc Track https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
cvssv3.1 6.3 https://github.com/rails/rails/blob/a967d355c6fee9ad9b8bd115d43bc8b0fc207e7e/activestorage/app/controllers/active_storage/direct_uploads_controller.rb#L14
generic_textual MODERATE https://github.com/rails/rails/blob/a967d355c6fee9ad9b8bd115d43bc8b0fc207e7e/activestorage/app/controllers/active_storage/direct_uploads_controller.rb#L14
ssvc Track https://github.com/rails/rails/blob/a967d355c6fee9ad9b8bd115d43bc8b0fc207e7e/activestorage/app/controllers/active_storage/direct_uploads_controller.rb#L14
cvssv3.1 6.3 https://nvd.nist.gov/vuln/detail/CVE-2023-51447
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2023-51447
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/decidim/decidim
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

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none

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unchanged

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Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/decidim/decidim/commit/aaf72787cf18beeeb6a771c1f7cbb7654b073423
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

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none

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2024-02-21T19:26:23Z/ Found at https://github.com/decidim/decidim/commit/aaf72787cf18beeeb6a771c1f7cbb7654b073423
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/decidim/decidim/pull/11612
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2024-02-21T19:26:23Z/ Found at https://github.com/decidim/decidim/pull/11612
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/decidim/decidim/releases/tag/v0.27.5
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

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none


Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2024-02-21T19:26:23Z/ Found at https://github.com/decidim/decidim/releases/tag/v0.27.5
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/decidim/decidim/releases/tag/v0.28.0
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2024-02-21T19:26:23Z/ Found at https://github.com/decidim/decidim/releases/tag/v0.28.0
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2024-02-21T19:26:23Z/ Found at https://github.com/decidim/decidim/security/advisories/GHSA-9w99-78rj-hmxq
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://github.com/rails/rails/blob/a967d355c6fee9ad9b8bd115d43bc8b0fc207e7e/activestorage/app/controllers/active_storage/direct_uploads_controller.rb#L14
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none


Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2024-02-21T19:26:23Z/ Found at https://github.com/rails/rails/blob/a967d355c6fee9ad9b8bd115d43bc8b0fc207e7e/activestorage/app/controllers/active_storage/direct_uploads_controller.rb#L14
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2023-51447
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

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low

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none

Exploit Prediction Scoring System (EPSS)
Percentile 0.65858
EPSS Score 0.00487
Published At June 11, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-11T17:20:39.417941+00:00 Vulnrichment Import https://github.com/cisagov/vulnrichment/blob/develop/2023/51xxx/CVE-2023-51447.json 38.6.0