Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 4.2.0-beta1 and prior to version 4.2.0-rc2, by crafting specific input, attackers can inject arbitrary data into HTTP requests issued by Mastodon. This can be used to perform confused deputy attacks if the server configuration includes ALLOWED_PRIVATE_ADDRESSES to allow access to local exploitable services. Version 4.2.0-rc2 has a patch for the issue.
CVE-2023-42450
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.5% (37th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 34EG Risk 34/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability0% × 15%CISA SSVC: Track at every mission impact level.Action: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation. - EPSS PROB
- 0.5%
- EPSS %ILE
- 37th
- KEV
- Not listed
CISA SSVCTrack at every mission impact level.
A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
September 19, 2023
Last Modified
June 17, 2026
References (4)
- security-advisories@githubhttps://github.com/mastodon/mastodon/commit/94893cf24fc95b32cc7a756262acbe008c20a9d2
- security-advisories@githubhttps://github.com/mastodon/mastodon/security/advisories/GHSA-hcqf-fw2r-52g4
- af854a3a-2127-422b-91ae-364da2661108https://github.com/mastodon/mastodon/commit/94893cf24fc95b32cc7a756262acbe008c20a9d2
- af854a3a-2127-422b-91ae-364da2661108https://github.com/mastodon/mastodon/security/advisories/GHSA-hcqf-fw2r-52g4
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 33× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 200 total refreshes for this CVE.
- 2026-10-09 20:05 UTCEPSS rescore
- 2026-10-08 17:06 UTCEPSS rescore
- 2026-10-07 23:46 UTCEPSS rescore
- 2026-10-06 15:15 UTCEPSS rescore
- 2026-10-05 17:41 UTCEPSS rescore
- 2026-10-04 23:20 UTCEPSS rescore
- 2026-10-03 14:23 UTCEPSS rescore
- 2026-10-03 14:23 UTCEPSS rescore
- 2026-10-01 19:48 UTCEPSS rescore
- 2026-09-30 16:30 UTCEG score recompute
- 2026-09-30 15:01 UTCEPSS rescore
- 2026-09-29 15:17 UTCEPSS rescore
- 2026-09-28 13:49 UTCEPSS rescore
- 2026-09-28 13:49 UTCEPSS rescore
- 2026-09-27 13:42 UTCEPSS rescore
- 2026-09-27 13:42 UTCEPSS rescore
- 2026-09-26 15:56 UTCEPSS rescore
- 2026-09-26 00:22 UTCEPSS rescore
- 2026-09-24 14:01 UTCEPSS rescore
- 2026-09-24 14:01 UTCEPSS rescore
- 2026-09-23 13:46 UTCEPSS rescore
- 2026-09-22 23:02 UTCOSV refresh
- 2026-09-20 20:14 UTCEPSS rescore
- 2026-09-20 20:14 UTCEPSS rescore
- 2026-09-18 19:25 UTCEPSS rescore
Show 75 moreShow fewer
- 2026-09-17 19:25 UTCEPSS rescore
- 2026-09-16 14:06 UTCEPSS rescore
- 2026-09-16 14:06 UTCEPSS rescore
- 2026-09-16 05:11 UTCEPSS rescore
- 2026-09-13 16:44 UTCEPSS rescore
- 2026-09-12 14:58 UTCEPSS rescore
- 2026-09-11 14:50 UTCEPSS rescore
- 2026-09-11 09:34 UTCEPSS rescore
- 2026-09-08 21:58 UTCEPSS rescore
- 2026-09-07 15:59 UTCEPSS rescore
- 2026-09-06 13:45 UTCEPSS rescore
- 2026-09-06 13:45 UTCEPSS rescore
- 2026-09-05 15:26 UTCEPSS rescore
- 2026-09-04 13:58 UTCEPSS rescore
- 2026-09-04 05:04 UTCEPSS rescore
- 2026-09-03 17:59 UTCOSV refresh
- 2026-09-02 14:09 UTCEPSS rescore
- 2026-09-01 13:51 UTCEPSS rescore
- 2026-08-30 19:15 UTCEPSS rescore
- 2026-08-30 01:20 UTCEPSS rescore
- 2026-08-28 21:39 UTCEPSS rescore
- 2026-08-27 14:23 UTCEPSS rescore
- 2026-08-26 14:44 UTCEPSS rescore
- 2026-08-26 14:43 UTCEPSS rescore
- 2026-08-25 13:46 UTCEPSS rescore
- 2026-08-23 00:17 UTCEPSS rescore
- 2026-08-21 23:47 UTCEPSS rescore
- 2026-08-20 22:53 UTCEPSS rescore
- 2026-08-19 17:02 UTCEPSS rescore
- 2026-08-19 17:02 UTCEPSS rescore
- 2026-08-18 13:46 UTCEPSS rescore
- 2026-08-17 13:45 UTCEPSS rescore
- 2026-08-17 07:01 UTCOSV refresh
- 2026-08-16 14:54 UTCEPSS rescore
- 2026-08-16 02:12 UTCEPSS rescore
- 2026-08-15 01:28 UTCEPSS rescore
- 2026-08-15 01:28 UTCEPSS rescore
- 2026-08-13 21:58 UTCEPSS rescore
- 2026-08-12 13:48 UTCEPSS rescore
- 2026-08-11 13:39 UTCEPSS rescore
- 2026-08-09 13:44 UTCEPSS rescore
- 2026-08-09 13:44 UTCEPSS rescore
- 2026-08-08 16:35 UTCEPSS rescore
- 2026-08-07 16:25 UTCEPSS rescore
- 2026-08-06 13:45 UTCEPSS rescore
- 2026-08-05 19:15 UTCEPSS rescore
- 2026-08-04 15:07 UTCEPSS rescore
- 2026-08-03 10:34 UTCEPSS rescore
- 2026-08-03 10:34 UTCEPSS rescore
- 2026-08-02 02:25 UTCEPSS rescore
- 2026-08-02 02:25 UTCEPSS rescore
- 2026-08-02 02:06 UTCOSV refresh
- 2026-08-01 04:14 UTCEPSS rescore
- 2026-08-01 04:13 UTCEPSS rescore
- 2026-07-30 16:26 UTCEPSS rescore
- 2026-07-30 16:26 UTCEPSS rescore
- 2026-07-30 01:28 UTCEPSS rescore
- 2026-07-30 01:28 UTCEPSS rescore
- 2026-07-28 15:34 UTCEPSS rescore
- 2026-07-28 15:34 UTCEPSS rescore
- 2026-07-26 14:52 UTCEPSS rescore
- 2026-07-26 14:52 UTCEPSS rescore
- 2026-07-25 14:16 UTCEPSS rescore
- 2026-07-24 14:16 UTCEPSS rescore
- 2026-07-23 14:16 UTCEPSS rescore
- 2026-07-23 14:16 UTCEPSS rescore
- 2026-07-23 02:26 UTCEG score recompute
- 2026-07-22 23:13 UTCEG score recompute▲ 2.10
- 2026-07-22 14:06 UTCEPSS rescore
- 2026-07-21 15:23 UTCEPSS rescore
- 2026-07-21 15:23 UTCEPSS rescore
- 2026-07-20 17:06 UTCEPSS rescore
- 2026-07-19 14:29 UTCEPSS rescore
- 2026-07-19 02:27 UTCEPSS rescore
- 2026-07-18 10:03 UTCEPSS rescore
Related CVEs(same CWE)
Same CWE
10 shownCWE-113 · CWE-918
Frequently asked(5)
What is CVE-2023-42450?
When was CVE-2023-42450 disclosed?
Is CVE-2023-42450 actively exploited?
What is the CVSS score of CVE-2023-42450?
How do I remediate CVE-2023-42450?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2023-42450
Is Your Infrastructure Affected by CVE-2023-42450?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.