CVE-2026-77581

HIGHPre-NVD 8.68.6
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.6 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). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Elevated
8.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.6Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

BentoPDF is a client-side PDF toolkit that is self hostable. In 2.8.6 and earlier, the certificate and timestamp CORS proxy in cloudflare/cors-proxy-worker.js uses isPrivateOrReservedHost() to validate a supplied hostname separately from the DNS resolution used by fetch(targetUrl), allowing an attacker-controlled hostname to resolve to an internal or reserved destination after validation. A certificate-like path can satisfy ALLOWED_PATH_PATTERNS, and direct clients can forge the browser-oriented Origin header. Deployments without PROXY_SECRET skip the optional signature check, while the signature is an anti-abuse measure rather than a destination-security boundary. The proxy has a 10 MB response limit and can relay response bodies from reachable destinations. The advisory identifies both the official Worker deployment and self-hosted instances as impacted where the Worker execution environment can reach internal or reserved destinations. This vulnerability is fixed in 2.8.7.

CVSS v3
8.6
EG Score
8.6(low)
EG Risk
70(Attend)
EG Risk 70/100SSVC: Attend

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
Severity86% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 24, 2026

Last Modified

September 24, 2026

Advisory Details (4)

Auto-updated Sep 24, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

CVE Fixes - v2.8.7

Patch available: alam00000/bentopdf v2.8.7

https://github.com/alam00000/bentopdf/releases/tag/v2.8.7
github_commit Patch Available

commit 58cd1a8893bf (alam00000/bentopdf)

Patch available: alam00000/bentopdf v2.8.7 (contains commit 58cd1a8893bf)

https://github.com/alam00000/bentopdf/commit/58cd1a8893bfe06e4a59a72adc2e7db00a8b9266
github_commit Patch Available

commit 45496fcd2ed6 (alam00000/bentopdf)

Patch available: alam00000/bentopdf v2.8.7 (contains commit 45496fcd2ed6)

https://github.com/alam00000/bentopdf/commit/45496fcd2ed6e02dcdde0d3839cc5024c091760c
github Patch Available🟡 PoC Available

SSRF in cors-proxy-worker.js via DNS-based hostname allowlist bypass · Advisory · alam00000/bentopdf · GitHub

https://github.com/alam00000/bentopdf/security/advisories/GHSA-5xjf-rr5x-pcfj

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 4× in last 7d / 4× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-09-24 16:34 UTCEG score recompute
  2. 2026-09-24 15:47 UTCEG score recompute
  3. 2026-09-24 15:32 UTCEG score recompute
  4. 2026-09-24 15:31 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-77581?
CVE-2026-77581 is a high vulnerability published on September 24, 2026. BentoPDF is a client-side PDF toolkit that is self hostable. In 2.8.6 and earlier, the certificate and timestamp CORS proxy in cloudflare/cors-proxy-worker.js uses isPrivateOrReservedHost() to validate a supplied hostname separately from the DNS resolution used by fetch(targetUrl), allowing an…
When was CVE-2026-77581 disclosed?
CVE-2026-77581 was first published in the National Vulnerability Database on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-77581?
CVE-2026-77581 has a CVSS v3 base score of 8.6 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-77581?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77581, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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