CVE-2026-46348
Mastodon SSRF via loopback allows access to private resources.
Is CVE-2026-46348 being exploited?
Not confirmed. CVE-2026-46348 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.41% probability of exploitation in the next 30 days.
How severe is CVE-2026-46348?
CVE-2026-46348 is rated High. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-46348?
Yes. A fix has been recorded for CVE-2026-46348. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-46348 affect?
CVE-2026-46348 affects Mastodon server (<4.5.10, <4.4.17, <4.3.23). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-46348?
Upgrade to 4.5.10, 4.4.17, or 4.3.23
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker can force Mastodon to contact loopback interfaces via a crafted IP, exposing private services/data.
Immediate action required
- affected>= 4.5.0-beta.1 and < 4.5.10
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.