CVE-2026-109966

yt-dlp-web-ui through 4.0.0 Argument Injection via Service.Formats JSON-RPC Method

CVSS score

6.9

EPSS probability

—

Risk score

0.7

Published

7 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

Impact on My Inventory

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Vulnerability description

CVE AI research

The stored explanation is shown at once; refreshing evaluates the sources again.

DayBreach AI Explanation

Verified against sources

yt-dlp-web-ui up to 4.0.0 Argument Injection (Service.Formats JSON‑RPC)

Sources read

Source agreement

0/2

Evidence confidence

%44

Short explanation

yt-dlp-web-ui versions 0‑4.0.0 allow injection of yt‑dlp options via a dash‑prefixed URL parameter to the Service.Formats JSON‑RPC method. Attackers can use /rpc/http or /rpc/ws to make the server load attacker‑chosen JSON files and reflect their contents in responses.

Why does it matter?

This unauthenticated remote exploit enables attackers to read server files and potentially execute additional commands.

What should be done?

Restrict access to RPC endpoints
Validate and sanitize URL parameters
Monitor for suspicious RPC requests
Follow vendor advisory when released
Consider upgrading to a patched version if available

Note on uncertainty

2 alanda kaynak uyuşmazlığı var. DayBreach bu değerleri saklamadı; kaynak karşılaştırması aşağıda gösteriliyor.

Chain of evidence and sources3 verified claims

Bu açık, Service.Formats JSON‑RPC metoduna dash‑önekli URL parametresi gönderilerek yt‑dlp seçeneklerinin enjekte edilmesine izin verir (S0,S1).

S0 · daybreach-canonical S1 · cvelist

Saldırgan, /rpc/http veya /rpc/ws üzerinden sunucunun dosya sistemindeki saldırgan‑kontrolündeki JSON dosyasını yükletebilir ve yanıt içinde yansıtabilir (S0,S1).

S0 · daybreach-canonical S1 · cvelist

CISA KEV listesinde aktif istismar bulunmamakta; yama durumu UNKNOWN olarak raporlanmıştır, bu nedenle resmi bir düzeltme mevcut olmayabilir (S0).

S0 · daybreach-canonical

Show the technical text from the sources

yt-dlp-web-ui through 4.0.0 contains an argument injection vulnerability that allows unauthenticated remote attackers to inject yt-dlp options by supplying a dash-prefixed url parameter to the Service.Formats JSON-RPC method. Attackers can send values like --load-info-json via /rpc/http or /rpc/ws to make yt-dlp load attacker-chosen JSON files from the server filesystem, with contents reflected in responses.

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CWE: CWE-88

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-109966 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	marcopiovanello	yt-dlp-web-ui	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
6.9	CVSS V4_0	MEDIUM	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N	CVE CNA
6.9	CVSS V40	MEDIUM	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD
5.3	CVSS V3_1	MEDIUM	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N	CVE CNA
5.3	CVSS V31	MEDIUM	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N	NVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-109966 is associated with the following CWEs:

CWE-88: Common Weakness Enumeration Entry CWE-88

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-109966 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

UserGerekmiyor

Official Sources and Advisories

https://github.com/vazzzy071-crypto/security-advisories/blob/main/advisories/2026-10-marcopiovanello-yt-dlp-web-ui-rpc-arg-injection.mdvendor-advisory https://github.com/marcopiovanello/yt-dlp-web-ui/blob/v4.0.0/server/formats/parser.govendor-advisory https://github.com/marcopiovanello/yt-dlp-web-uivendor-advisory VulnCheck Advisory: yt-dlp-web-ui through 4.0.0 Argument Injection via Service.Formats JSON-RPC Methodvendor-advisory

CVSS Vector Radar Chart

6.9 / 10

Vulnerability Scoring Details

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User InteractionNone required

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)None

Availability (Erişilebilirlik)None

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

marcopiovanello

Weakness Type (CWE & CAPEC)

CWE-88

Similar Vulnerabilities

8.7

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yt-dlp-web-ui through 4.0.0 NULL Pointer Dereference DoS via Service.Formats

VendormarcopiovanelloProductyt-dlp-web-ui

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