CVE-2026-61500

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-13. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-43505 (ENISA EUVD) · GHSA-xxrm-3f86-v97j (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.9%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Rejetto HFS 3.0.0 through 3.2.0 derives its session-cookie signing key from the non-cryptographic Math.random() generator and discloses outputs of the same generator to unauthenticated clients during login. A remote attacker can collect a small number of login responses, reconstruct the generator's state, recover the signing key, and forge a valid administrator session cookie, leading to full administrative access and remote code execution via the server_code configuration feature.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
60
EG Risk 60/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation1.9% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
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 none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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
1.9%
EPSS %ILE
79th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-28). 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: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: 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 none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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

July 13, 2026

Last Modified

October 24, 2026

Advisory Details (2)

Auto-updated Oct 26, 2026
Patch available. Sources: github_release.
Web page

Rejetto HFS < 3.2.1 Session Forgery via Predictable Signing Key | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rejetto-hfs-session-forgery-via-predictable-signing-key
GitHub release Patch Available

3.2.1

Patch available: rejetto/hfs v3.2.1

https://github.com/rejetto/hfs/releases/tag/v3.2.1

Vendor Advisories for CVE-2026-61500(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 75× 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.

Showing the most recent 100 of 431 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 331 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 16:33 UTCEPSS rescoreEPSS 1.9% · 79th percentile
  2. 2026-10-29 14:14 UTCEG score recompute
  3. 2026-10-29 14:14 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-28 16:32 UTCEPSS rescoreEPSS 1.9% · 79th percentile
  5. 2026-10-28 13:46 UTCEG score recompute
  6. 2026-10-28 13:45 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 1.9% · 79th percentile
  8. 2026-10-27 13:04 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-27 03:32 UTCEG score recompute
  10. 2026-10-27 03:31 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-25 22:55 UTCEG score recompute
  12. 2026-10-25 22:55 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-25 16:33 UTCEPSS rescoreEPSS 1.9% · 79th percentile
  14. 2026-10-25 14:14 UTCEG score recompute
  15. 2026-10-24 22:26 UTCEG score recompute
  16. 2026-10-24 22:26 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-24 19:38 UTCEG score recompute
  18. 2026-10-24 19:38 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  20. 2026-10-23 19:10 UTCEG score recompute
  21. 2026-10-23 19:10 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-23 16:32 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  23. 2026-10-22 18:40 UTCEG score recompute
  24. 2026-10-22 18:40 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-22 16:35 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
Show 75 more
  1. 2026-10-21 18:08 UTCEG score recompute
  2. 2026-10-21 18:08 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-21 16:33 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  4. 2026-10-20 17:39 UTCEG score recompute
  5. 2026-10-20 17:39 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  7. 2026-10-19 17:11 UTCEG score recompute
  8. 2026-10-19 17:10 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-19 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  10. 2026-10-18 16:40 UTCEG score recompute
  11. 2026-10-18 16:39 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-18 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  13. 2026-10-18 03:25 UTCEG score recompute
  14. 2026-10-17 16:35 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  15. 2026-10-17 15:58 UTCEG score recompute
  16. 2026-10-17 15:58 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-16 16:43 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  18. 2026-10-16 15:29 UTCEG score recompute
  19. 2026-10-16 15:28 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  21. 2026-10-15 14:56 UTCEG score recompute
  22. 2026-10-15 14:56 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  24. 2026-10-14 09:24 UTCEG score recompute
  25. 2026-10-14 09:23 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  27. 2026-10-13 06:52 UTCEG score recompute
  28. 2026-10-13 06:51 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  30. 2026-10-12 15:50 UTCEG score recompute
  31. 2026-10-12 06:21 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  32. 2026-10-11 19:34 UTCEG score recompute
  33. 2026-10-11 16:49 UTCEG score recompute
  34. 2026-10-11 14:11 UTCEG score recompute
  35. 2026-10-11 13:49 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  36. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  37. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  38. 2026-10-08 17:13 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  39. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  40. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  41. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  42. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  43. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  44. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  45. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  46. 2026-10-01 15:30 UTCEG score recompute
  47. 2026-10-01 15:30 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  48. 2026-10-01 14:12 UTCEG score recompute
  49. 2026-10-01 14:12 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  51. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  52. 2026-09-28 13:22 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-09-28 09:31 UTCEG score recompute
  54. 2026-09-28 09:31 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  56. 2026-09-24 10:05 UTCEG score recompute
  57. 2026-09-24 10:05 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  58. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  59. 2026-09-23 12:09 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  60. 2026-09-23 08:13 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-09-23 04:20 UTCEG score recompute
  62. 2026-09-23 04:20 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  64. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  65. 2026-09-18 10:06 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-09-18 05:02 UTCEG score recompute
  67. 2026-09-18 05:02 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  69. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  70. 2026-09-14 11:07 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-09-14 07:13 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-09-14 03:22 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-09-13 23:31 UTCEG score recompute
  74. 2026-09-13 23:31 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-09-13 16:30 UTCGHSA enrichmentGHSA-xxrm-3f86-v97j · GitHub severity CRITICAL · GitHub CVSS 9.8

Frequently asked(5)

What is CVE-2026-61500?
CVE-2026-61500 is a critical-severity vulnerability; its CVE record was published on July 13, 2026. Rejetto HFS 3.0.0 through 3.2.0 derives its session-cookie signing key from the non-cryptographic Math.random() generator and discloses outputs of the same generator to unauthenticated clients during login. A remote attacker can collect a small number of login responses, reconstruct the generator's…
When was CVE-2026-61500 made public?
CVE-2026-61500 was made public on July 13, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on July 13, 2026. EchelonGraph's copy of the record carries a last-modified date of October 24, 2026; the record at its source may have been updated since.
Is CVE-2026-61500 actively exploited?
CVE-2026-61500 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.9% probability of exploitation in the next 30 days (79th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-61500?
CVE-2026-61500 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-61500?
A fix for CVE-2026-61500 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-61500 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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