CVE-2023-36459

mediumpriority · track · 24EPSS 0.012 · 68 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.22% (68th) EPSS

CVSS 6.1 · medium

Is it mine?

12 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 1.3 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker using carefully crafted oEmbed data can bypass the HTML sanitization performed by Mastodon and include arbitrary HTML in oEmbed preview cards. This introduces a vector for cross-site scripting (XSS) payloads that can be rendered in the user's browser when a preview card for a malicious link is clicked through. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

cvss

Technical severity, 0–10. One row per scoring source.

9.3

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 5.6–9.3

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 2.7

v3.19.3criticalAV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Nsecondary · FSTEC (BDU) RU

v3.19.3criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Nsecondary · ENISA EU

v3.19.3criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:Nsecondary · security-advisories@github.comexploitability 2.8 · impact 5.8

v3.15.6mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USCWE-79US

affected products (12)

Products and version ranges known to be affected.

mastodon mastodon1.3, → 3.5.9enisa_euvdEU
mastodon mastodon4.0.0, → 4.0.5enisa_euvdEU
mastodon mastodon4.1.0, → 4.1.3enisa_euvdEU
Mastodon gGmbH Mastodon≤ 3.5.9fstec_bduRU
Mastodon gGmbH Mastodon4.0.0 → 4.0.5fstec_bduRU
Mastodon gGmbH Mastodon4.1.0 → 4.1.3fstec_bduRU
joinmastodon mastodon1.3 → 3.5.9nvdUScpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*
joinmastodon mastodon4.0.0 → 4.0.5nvdUScpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*
joinmastodon mastodon4.1.0 → 4.1.3nvdUScpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*
Bitnami mastodon1.3.0 → 3.5.9osvUSpkg:bitnami/mastodon
Bitnami mastodon4.0.0 → 4.0.5osvUSpkg:bitnami/mastodon
Bitnami mastodon4.1.0 → 4.1.3osvUSpkg:bitnami/mastodon

advisories (1)

Vendor and ecosystem advisories describing this.

BIT-mastodon-2023-36459Mastodon vulnerable to Cross-site Scripting through oEmbed preview cards2024-03-06vendor · osvUS
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 1.3 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker using carefully crafted oEmbed data can bypass the HTML sanitization performed by Mastodon and include arbitrary HTML in oEmbed preview cards. This introduces a vector for cross-site scripting (XSS) payloads that can be rendered in the user's browser when a preview card for a malicious link is clicked through. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv nvd NVD CVE.org MITRE

published 2023-07-06modified 2026-06-17

references (19)

External citations — patches, advisories, analysis.

scry

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