Misskey is an open source, federated social media platform. From 12.0.0 until 2026.7.0, the RSS components display feed item links from configured feeds without verifying their URL schemes. Missing URL scheme verification allows an attacker who controls feed content to provide an unsafe-scheme link that causes script execution when a user clicks it in an RSS widget. This issue is fixed in version 2026.7.0.
CVE-2026-104816
HIGHPre-NVD 8.58.5
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from a secondary CVSS source
Sources: a secondary CVSS source
8.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.5Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 8.5
- EG Score
- 8.5HIGHlow confidence
- EG Risk
- 53EG Risk 53/100
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 computed (value × EchelonGraph’s weight)Severity85% × 45%The EG Score, 8.5 of 10.Exploitation0% × 40%No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
October 13, 2026
Last Modified
October 13, 2026
Advisory Details (4)
Auto-updated Oct 13, 2026Patch available. Sources: github_commit, github_release, github, github_pr.
GitHub release Patch Available
2026.7.0
Patch available: misskey-dev/misskey 2026.7.0
https://github.com/misskey-dev/misskey/releases/tag/2026.7.0GitHub commit Patch Available
commit 8dd59a8c06da (misskey-dev/misskey)
Patch available: misskey-dev/misskey 2026.7.0 (contains commit 8dd59a8c06da)
https://github.com/misskey-dev/misskey/commit/8dd59a8c06da49b8f302d902d73d04397ee29366GitHub pull request Patch Available
fix: RSS系ウィジェットにフィードURL検査機構を追加
Patch available: misskey-dev/misskey 2026.7.0 (PR #17831 merged 2026-07-31)
https://github.com/misskey-dev/misskey/pull/17831GitHub advisoryMentions a patch (unverified)
Cross-site scripting in RSS feed item links · Advisory · misskey-dev/misskey · GitHub
https://github.com/misskey-dev/misskey/security/advisories/GHSA-p73x-6qrq-34jcWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-10-13 21:29 UTCEG score recompute
- 2026-10-13 20:30 UTCEG score recompute
- 2026-10-13 19:53 UTCEG score recompute
- 2026-10-13 18:52 UTCEG score recomputeFirst assessed: 8.5 HIGH
- 2026-10-13 18:49 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-104816?
CVE-2026-104816 is a high-severity vulnerability; its CVE record was published on October 13, 2026. Misskey is an open source, federated social media platform. From 12.0.0 until 2026.7.0, the RSS components display feed item links from configured feeds without verifying their URL schemes. Missing URL scheme verification allows an attacker who controls feed content to provide an unsafe-scheme link…
When was the CVE record for CVE-2026-104816 published?
The CVE record for CVE-2026-104816 was published on October 13, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 13, 2026; the record at its source may have been updated since.
What is the CVSS score of CVE-2026-104816?
CVE-2026-104816 has a CVSS base score of 8.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-104816?
A fix for CVE-2026-104816 is available: update to the fixed version the vendor names in its advisory.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-104816
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