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Fencer Vulns
critical 9.1

CVE-2026-56081 json

Cap-go - Account Lockout via 2FA Misconfiguration on Unverified Email

published 2026-06-19 4 mo ago modified 2026-11-08 26 h ago also EUVD-2026-38095

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

Cap-go before 12.128.2 contains an authentication logic flaw that lets an attacker register and control an account bound to a victim's email address before that email is verified. By enabling two-factor authentication on the pre-registered account, the attacker gains control over the account claimed under the victim's identity, allowing them to read and modify its state and enforce organization-level policies, while the legitimate user is denied access to the account tied to their own email.

Patch / fix

  • Cap-go capgo 12.128.2

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Cap-go/capgo/security/advisories/GHSA-j4cx-5pw6-5v5j referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Cap-go capgo

Classification

Weakness
  • CWE-640 Weak Password Recovery Mechanism for Forgotten Password

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.