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Fencer Intel
critical 9.8

CVE-2020-8986 json

lib/NSSDropbox.php in ZendTo prior to 5.22-2 Beta failed to properly check for equality when validating the session cookie, allowing an att…

published 6y ago modified 4mo ago also EUVD-2020-29816

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

lib/NSSDropbox.php in ZendTo prior to 5.22-2 Beta failed to properly check for equality when validating the session cookie, allowing an attacker to gain administrative access with a large number of requests.

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Exploit prediction

1.54% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-754 Improper Check for Unusual or Exceptional Conditions

References

Sources

Fencer Intel 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.