CVE-2025-65849

CRITICALPre-NVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.1 under CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit probability: 0.2% (14th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from CISA-ADP (Vulnrichment) CVSS v3.1
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS

Also known asEUVD-2025-201806 (ENISA EUVD) · GHSA-mpmc-qchh-r9q8 (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan mitigationNo fix is confirmed yet: check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule 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: 0.2%CVSS: 9.1Exploit: None knownExposed services: Not assessed

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

A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the Proof-of-Work nonce in constant time via mathematical deduction. NOTE: this is disputed by the Supplier because the product's objective is "to discourage automated scraping / bots, not guarantee resistance to determined attackers." The documentation states “the goal is not to provide a secure cryptographic algorithm but to use a proof-of-work mechanism that allows any capable device to decrypt the hidden data.”

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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: No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high.
EPSS PROB
0.2%
EPSS %ILE
14th
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.CISA-ADP (Vulnrichment) CVSS v3.1 · CVSS v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). 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.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.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).

No fix is confirmed yet. Check the vendor's advisory for a fixed release; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule 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.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.

The score's inputs: 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

December 8, 2025

Last Modified

October 18, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
No fix on record yet.
Web page

GitHub - eternal-flame-AD/altcha-deobfs: Constant time deobfuscation of text from Altcha's "Proof-of-Work" obfuscation scheme. · GitHub

https://github.com/eternal-flame-AD/altcha-deobfs
Web page

altcha/src/helpers.ts at 154f874cbcdd4e639783463130d13988a2bd1bdc · altcha-org/altcha · GitHub

https://github.com/altcha-org/altcha/blob/154f874cbcdd4e639783463130d13988a2bd1bdc/src/helpers.ts#L170-L194
Web page

Obfuscation | ALTCHA

https://altcha.org/docs/v2/obfuscation/

Vendor Advisories for CVE-2025-65849(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
npmaltcha—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
altcha—
  • 0.8.0 through 2.2.4: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 58× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 292 rows 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 192 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 02:20 UTCEchelonGraph re-scored
  2. 2026-11-13 02:20 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  3. 2026-11-12 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-11-12 02:56 UTCEchelonGraph re-scored
  5. 2026-11-12 02:56 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  6. 2026-11-11 16:36 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-11-11 03:31 UTCEchelonGraph re-scored
  8. 2026-11-11 03:31 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  9. 2026-11-10 16:41 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  10. 2026-11-10 04:05 UTCEchelonGraph re-scored
  11. 2026-11-10 04:05 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  12. 2026-11-09 04:38 UTCEchelonGraph re-scored
  13. 2026-11-09 04:38 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  14. 2026-11-08 16:37 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  15. 2026-11-08 05:14 UTCEchelonGraph re-scored
  16. 2026-11-08 05:14 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  17. 2026-11-07 16:37 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  18. 2026-11-07 05:49 UTCEchelonGraph re-scored
  19. 2026-11-07 05:49 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  20. 2026-11-06 16:34 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  21. 2026-11-06 06:25 UTCEchelonGraph re-scored
  22. 2026-11-06 06:25 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  23. 2026-11-05 16:35 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  24. 2026-11-05 07:01 UTCEchelonGraph re-scored
  25. 2026-11-05 07:01 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
Show 75 more
  1. 2026-11-04 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  2. 2026-11-04 07:36 UTCEchelonGraph re-scored
  3. 2026-11-04 07:36 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  4. 2026-11-03 16:45 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  5. 2026-11-03 08:12 UTCEchelonGraph re-scored
  6. 2026-11-03 08:11 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  7. 2026-11-02 16:43 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  8. 2026-11-02 08:46 UTCEchelonGraph re-scored
  9. 2026-11-02 08:46 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  10. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  11. 2026-11-01 09:21 UTCEchelonGraph re-scored
  12. 2026-11-01 09:21 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8 · GitHub severity MODERATE
  13. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  14. 2026-10-31 09:56 UTCEchelonGraph re-scored
  15. 2026-10-31 09:56 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  16. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  17. 2026-10-30 10:32 UTCEchelonGraph re-scored
  18. 2026-10-30 10:32 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  19. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  20. 2026-10-29 11:08 UTCEchelonGraph re-scored
  21. 2026-10-29 11:08 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  22. 2026-10-28 16:30 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  23. 2026-10-28 11:37 UTCEchelonGraph re-scored
  24. 2026-10-28 11:37 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  25. 2026-10-27 16:30 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  26. 2026-10-27 11:55 UTCEchelonGraph re-scored
  27. 2026-10-27 11:55 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  28. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  29. 2026-10-26 12:31 UTCEchelonGraph re-scored
  30. 2026-10-26 12:31 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  31. 2026-10-25 16:31 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  32. 2026-10-25 16:09 UTCEchelonGraph re-scored
  33. 2026-10-25 13:02 UTCEchelonGraph re-scored
  34. 2026-10-25 13:02 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  35. 2026-10-24 16:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  36. 2026-10-24 13:37 UTCEchelonGraph re-scored
  37. 2026-10-24 13:37 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  38. 2026-10-23 16:30 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  39. 2026-10-23 14:03 UTCEchelonGraph re-scored
  40. 2026-10-23 14:02 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  41. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  42. 2026-10-22 14:36 UTCEchelonGraph re-scored
  43. 2026-10-22 14:36 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  44. 2026-10-21 16:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  45. 2026-10-21 14:38 UTCEchelonGraph re-scored
  46. 2026-10-21 14:38 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  47. 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  48. 2026-10-20 14:59 UTCEchelonGraph re-scored
  49. 2026-10-20 14:59 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  50. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  51. 2026-10-19 14:53 UTCEchelonGraph re-scored
  52. 2026-10-19 14:52 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  53. 2026-10-18 15:27 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  54. 2026-10-18 05:19 UTCEchelonGraph re-scored
  55. 2026-10-17 19:13 UTCEchelonGraph re-scored
  56. 2026-10-17 19:13 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  57. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  58. 2026-10-16 19:49 UTCEchelonGraph re-scored
  59. 2026-10-16 19:49 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  60. 2026-10-16 16:39 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  61. 2026-10-15 17:05 UTCEchelonGraph re-scored
  62. 2026-10-15 17:04 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  63. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  64. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  65. 2026-10-14 11:05 UTCEchelonGraph re-scored
  66. 2026-10-14 11:05 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  67. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  68. 2026-10-13 09:46 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  69. 2026-10-12 16:49 UTCEchelonGraph re-scored
  70. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  71. 2026-10-12 10:18 UTCGHSA enrichmentGHSA-mpmc-qchh-r9q8
  72. 2026-10-11 20:23 UTCEchelonGraph re-scored
  73. 2026-10-11 18:35 UTCEchelonGraph re-scored
  74. 2026-10-11 15:10 UTCEchelonGraph re-scored
  75. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile

Frequently asked(5)

What is CVE-2025-65849?
CVE-2025-65849 is a critical-severity vulnerability; its CVE record was published on December 8, 2025. A cryptanalytic break in Altcha Proof-of-Work obfuscation mode version 0.8.0 and later allows for remote visitors to recover the Proof-of-Work nonce in constant time via mathematical deduction. NOTE: this is disputed by the Supplier because the product's objective is "to discourage automated…
When was the CVE record for CVE-2025-65849 published?
The CVE record for CVE-2025-65849 was published on December 8, 2025. 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 October 18, 2026; the record at its source may have been updated since.
Is CVE-2025-65849 actively exploited?
CVE-2025-65849 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2025-65849?
CVE-2025-65849 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2025-65849?
No fix for CVE-2025-65849 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2025-65849 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-65849

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