Categories
CVE-2026-76239 medium CVSS 6.3

SSRF (Server-Side Request Forgery) in Stigmem (CVE-2026-76239)

Summary

SSRF in Stigmem (CVE-2026-76239). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

Summary

Stigmem allows an authenticated user to create a webhook subscription with a user-controlled delivery_address. That value is stored and later used directly by the subscription delivery worker as the destination of a server-side HTTP POST request.

The codebase already contains an outbound SSRF guard, assert_safe_url(), which blocks loopback, private, link-local, and metadata-style destinations. However, the subscription webhook delivery path does not appear to apply this guard either when the subscription is created or immediately before delivery.

As a result, an authenticated user can configure a webhook destination such as http://127.0.0.1:9999/ssrf, trigger a matching fact-change event, and cause the Stigmem server to issue a server-side HTTP request to an internal loopback address.

Details

Relevant files:

node/src/stigmem_node/routes/subscriptions.py
node/src/stigmem_node/subscription_delivery.py
node/src/stigmem_node/models/subscriptions.py
node/src/stigmem_node/utility/net_util.py

SubscriptionCreateRequest accepts delivery_address as a plain string and validates only that it has a minimum length:

class SubscriptionCreateRequest(BaseModel):
    target: str = Field(..., min_length=1)
    on_change: str = Field(...)
    delivery_address: str = Field(..., min_length=1)

The create route persists this value directly:

conn.execute(
    """INSERT INTO subscriptions
       (id, subscriber_identity, target, target_kind, on_change,
        de…

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-76239 has been found in Stigmem.
Risk of unauthorized operations or information disclosure. CVSS score: 6.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Stigmem CVE-2026-76239" on the vendor's site.

CVE-2026-76239 (Stigmem) — CWE-918 / CVSS v3 6.3
Attack vector: remote (network-reachable) / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

SSRF (CWE-918) exists in Stigmem.

📍 Affected scope

Check the vendor advisory for the affected versions of Stigmem.

🔥 Severity

Severity: Medium (CVSS 6.3/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Stigmem' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    grep -r 'Stigmem' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Stigmem を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Post-deployment verification verify
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

PyPI stigmem-node
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.0a11"}]}]

References

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