CVE-2023-36461

highpriority · track · 30EPSS 0.013 · 70 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.31% (70th) EPSS

CVSS 7.5 · high

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. When performing outgoing HTTP queries, Mastodon sets a timeout on individual read operations. Prior to versions 3.5.9, 4.0.5, and 4.1.3, a malicious server can indefinitely extend the duration of the response through slowloris-type attacks. This vulnerability can be used to keep all Mastodon workers busy for an extended duration of time, leading to the server becoming unresponsive. 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.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

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

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-770USCWE-770US

affected products (12)

Products and version ranges known to be affected.

mastodon mastodon≤ < 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 mastodon< 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 mastodon< 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-2023-36461Mastodon vulnerable to Denial of Service through slow HTTP responses2024-03-06vendor · osvUS
Mastodon is a free, open-source social network server based on ActivityPub. When performing outgoing HTTP queries, Mastodon sets a timeout on individual read operations. Prior to versions 3.5.9, 4.0.5, and 4.1.3, a malicious server can indefinitely extend the duration of the response through slowloris-type attacks. This vulnerability can be used to keep all Mastodon workers busy for an extended duration of time, leading to the server becoming unresponsive. 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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