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Vulnerabilities

Vulnerability · CVE-2025-65849

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 mathematic

Published Dec 8, 2025 · catalog updated Oct 18, 2026 · A cryptanalytic break in

Last checked Oct 29, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-65849. EPSS is 0.22%. Act only if a listed version of A cryptanalytic break in is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (A cryptanalytic break in).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Critical9.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.22%
Remediation
Vendor / distro source
Affected products
vendor n/a n/a n/a

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.”

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor n/a n/a n/an/a

How to fix CVE-2025-65849

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-65849. EPSS is 0.22%. Act only if a listed version of A cryptanalytic break in is installed.

Which versions are affected?

Compare what you have installed with n/a n/a n/a n/a. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-327: Use of a Broken or Risky Cryptographic Algorithm. EPSS 0.22%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 8, 2025 · NIST NVD

    Detected

    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 n

  2. Oct 18, 2026 · NIST NVD

    Updated

    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 n

Sources

  • CVE.orgVulnerability recordCVE-2025-65849

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-65849

    30-day exploitation probability 0.22%

    first.org
  • EUVDVulnerability recordEUVD-2025-201806

    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 discoura

    euvd.enisa.europa.eu
  • NIST NVDVulnerability recordCVE-2025-65849

    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 discoura

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • EUVDOct 27, 2026
  • FIRST EPSSOct 23, 2026
  • NIST NVDOct 18, 2026
  • CVE.orgOct 18, 2026