CVE Explorer
CVE-2026-23964
Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.5, 4.4.12, and 4.3.18, an insecure direct object reference in the web push subscription update endpoint lets any authenticated user update another user's push subscription by guessing or obtaining the numeric subscription id. This can be used to disrupt push notifications for other users and also leaks the web push subscription endpoint. Any user with a web push subscription is impacted, because ano
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"mastodon","vendor":"mastodon","versions":[{"status":"affected","version":"< 4.3.18"},{"status":"affected","version":">= 4.4.0, < 4.4.12"},{"status":"affected","version":">= 4.5.0, < 4.5.5"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-863","description":"CWE-863: Incorrect Authorization","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/problemTypes/0/descriptions/0
Source references
4 source assertions{"name":"https://github.com/mastodon/mastodon/releases/tag/v4.3.18","tags":["x_refsource_MISC"],"url":"https://github.com/mastodon/mastodon/releases/tag/v4.3.18"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/references/1
{"name":"https://github.com/mastodon/mastodon/releases/tag/v4.4.12","tags":["x_refsource_MISC"],"url":"https://github.com/mastodon/mastodon/releases/tag/v4.4.12"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/references/2
{"name":"https://github.com/mastodon/mastodon/releases/tag/v4.5.5","tags":["x_refsource_MISC"],"url":"https://github.com/mastodon/mastodon/releases/tag/v4.5.5"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/references/3
{"name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-f3q8-7vw3-69v4","tags":["x_refsource_CONFIRM"],"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-f3q8-7vw3-69v4"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:4490d43c14e7b367bf8d86c6720e68adeb6741119939a41632078a455e829346 · sha256:c530874683325c7f… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.