SSRF (Server-Side Request Forgery) in open-webui (CVE-2026-45331)
Summary
SSRF in open-webui (CVE-2026-45331). Confidential information can be exposed externally. Exploitable via validators. Mitigation: upgrade to 0.9.0 or later.
Original description
The description as published by the source.
SSRF Bypass via IPv6/IPv4-mapped IPv6/IPv4-reserved-ranges in validate_url()
Summary
validate_url() in backend/open_webui/retrieval/web/utils.py calls validators.ipv6(ip, private=True), but the validators library does NOT implement the private keyword for IPv6 — the call raises a ValidationError (which is falsy in a boolean context), so every IPv6 address passes the filter. In addition, IPv4-mapped IPv6 (::ffff:10.0.0.1) bypasses the IPv4 check entirely, and several reserved IPv4 ranges (0.0.0.0/8, 100.64.0.0/10, 192.0.0.0/24, etc.) are not blocked.
The vulnerability has existed since the validate_url() function was introduced and was NOT actually fixed by GHSA-c6xv-rcvw-v685 / CVE-2025-65958 despite that patch's intent. It affects every endpoint that calls validate_url(), including /api/v1/retrieval/process/web, /api/v1/images/edit, and others.
Affected code
backend/open_webui/retrieval/web/utils.py validate_url():
if validators.ipv6(ip, private=True): # ValidationError is falsy — never raises
raise ValueError(...)
Proof of concept
import validators
print(validators.ipv6("::1", private=True))
# ValidationError(func=ipv6, args={'reason': "ipv6() got an unexpected keyword argument 'private'", ...})
End-to-end exploit:
import requests, ipaddress
OPEN_WEBUI_URL = "https://target"
TOKEN = "..."
TARGET_IPV4 = "169.254.169.254" # AWS IMDSv1
mapped = "::ffff:" + TARGET_IPV4
requests.p…
Source: GitHub Security Advisories (Global) 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-2026-45331 has been found in open-webui.
Attackers can target a specific entry point like validators over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.5/10.
What to do: upgrade open-webui to 0.9.0 or later.
If unsure, ask your IT team or search "open-webui CVE-2026-45331" on the vendor's site.
CVE-2026-45331 (open-webui) — CWE-918 / CVSS v3 8.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: validators / private / ValidationError / ipaddress
Patched: 0.9.0 — apply immediately
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.
SSRF (CWE-918) exists in open-webui. Attackers reach the vulnerable code path via validators.
Check the vendor advisory for the affected versions of open-webui. Attack surface: validators / private / ValidationError / ipaddress.
Severity: High (CVSS 8.5/10). Confidential information can be exposed externally.
Update to 0.9.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'open-webui' . 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
-
1Identify exposure identify
grep -r 'open-webui' . | 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
open-webuiを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade open-webui to 0.9.0ステージング環境で 0.9.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-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
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com