CVE-2026-77581

HIGHPre-NVD 8.68.6
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (18th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-86229 (ENISA EUVD)Source: ENISA EUVD

8.6EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.6Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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
8.6HIGHmedium confidence
EG Risk
70
EG Risk 70/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity86% × 45%
Impact severity (EG Severity): CVSS 8.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (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
0.3%
EPSS %ILE
18th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.6): severity, escalated by confirmed exploitation. This CVE's 8.6 is its impact severity (EG Severity), not escalated.

EG Severity
8.6 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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 public PoC (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.

The score's inputs: 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

September 24, 2026

Last Modified

September 29, 2026

Advisory Details (4)

Auto-updated Sep 24, 2026
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 advisoryMentions a patch (unverified)

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 8× in last 7d / 47× 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.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  4. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  5. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  6. 2026-10-27 18:55 UTCEG score recompute
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  10. 2026-10-25 14:01 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  14. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  15. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  16. 2026-10-20 08:12 UTCEG score recompute
  17. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  18. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  19. 2026-10-18 03:11 UTCEG score recompute
  20. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  21. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  22. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  23. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  24. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  25. 2026-10-13 06:56 UTCEG score recompute
Show 40 more
  1. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  2. 2026-10-12 15:37 UTCEG score recompute
  3. 2026-10-11 19:23 UTCEG score recompute
  4. 2026-10-11 16:39 UTCEG score recompute
  5. 2026-10-11 13:57 UTCEG score recompute
  6. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  7. 2026-10-10 21:52 UTCEG score recompute
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  9. 2026-10-10 08:10 UTCEG score recompute
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  11. 2026-10-09 06:04 UTCEG score recompute
  12. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  13. 2026-10-08 17:01 UTCEG score recompute
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  15. 2026-10-06 21:33 UTCEG score recompute
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  17. 2026-10-05 19:26 UTCEG score recompute
  18. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  19. 2026-10-05 06:24 UTCEG score recompute
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  21. 2026-10-03 15:12 UTCEG score recompute
  22. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  23. 2026-10-03 02:11 UTCEG score recompute
  24. 2026-10-02 00:03 UTCEG score recompute
  25. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  26. 2026-09-30 21:35 UTCEG score recompute
  27. 2026-09-29 19:23 UTCEG score recompute
  28. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  29. 2026-09-29 01:33 UTCEG score recompute
  30. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  31. 2026-09-27 23:29 UTCEG score recompute
  32. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  33. 2026-09-26 21:23 UTCEG score recompute
  34. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  35. 2026-09-26 08:21 UTCEG score recompute
  36. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  37. 2026-09-24 16:34 UTCEG score recompute
  38. 2026-09-24 15:47 UTCEG score recompute
  39. 2026-09-24 15:32 UTCEG score recomputeFirst assessed: 8.6 HIGH
  40. 2026-09-24 15:31 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77581?
CVE-2026-77581 is a high-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-77581 published?
The CVE record for CVE-2026-77581 was published on September 24, 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 September 29, 2026; the record at its source may have been updated since.
Is CVE-2026-77581 actively exploited?
CVE-2026-77581 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77581?
CVE-2026-77581 has a CVSS base score of 8.6 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-77581?
A fix for CVE-2026-77581 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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