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Fencer Vulns
critical 9.8

CVE-2021-47157 json

The Kossy module before 0.60 for Perl allows JSON hijacking because of X-Requested-With mishandling.

published 2024-03-18 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33805

cvss
9.8
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 35%
public exploits
0
none known

Summary

The Kossy module before 0.60 for Perl allows JSON hijacking because of X-Requested-With mishandling.

Patch / fix

  • kossy kossy 0.60

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
23 mo ago

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • kossy kossy

Classification

Weakness

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.