CVE-2026-104817
An attacker can trigger unbounded outbound HTTP requests and synchronous parsing, exhausting instance resources, amplifying requests toward third-party servers, or probing network-reachable services even when federation is disabled.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Misskey is an open source, federated social media platform. From 12.112.1 until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting and response-size restrictions and performs synchronous XML parsing. An attacker can trigger unbounded outbound HTTP requests and synchronous parsing, exhausting instance resources, amplifying requests toward third-party servers, or probing network-reachable services even when federation is disabled. This issue is fixed in version 2026.7.0.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:L/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.46% probability · 40th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-405, CWE-770, CWE-918
- Source
- security-advisories@github.com
EPSS moved from 0.5% on 14 October 2026 to 0.5% on 26 October 2026.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.