CVE Explorer
CVE-2026-48028
Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing threat actors to remove JSON entries from valid signed activities from a third-party actor. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.
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":">= 4.5.0-beta.1, < 4.5.10"},{"status":"affected","version":">= 4.4.0-beta.1, < 4.4.17"},{"status":"affected","version":"< 4.3.23"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:77810bf7ddd7e7ad2294f68b94b1e05ab5da8f5839d882921c2ba8c4f1b6eba0 · sha256:24a75d0c54e2af88… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:77810bf7ddd7e7ad2294f68b94b1e05ab5da8f5839d882921c2ba8c4f1b6eba0 · sha256:24a75d0c54e2af88… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-354","description":"CWE-354: Improper Validation of Integrity Check Value","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:77810bf7ddd7e7ad2294f68b94b1e05ab5da8f5839d882921c2ba8c4f1b6eba0 · sha256:24a75d0c54e2af88… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-53m7-2wrh-q839","tags":["x_refsource_CONFIRM"],"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-53m7-2wrh-q839"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:77810bf7ddd7e7ad2294f68b94b1e05ab5da8f5839d882921c2ba8c4f1b6eba0 · sha256:24a75d0c54e2af88… · /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.