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Fencer Vulns
high 8.8

CVE-2021-21796 in the critical feed json

An exploitable use-after-free vulnerability exists in the JavaScript implementation of Nitro Pro PDF.

published 2021-10-18 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8968

cvss
8.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
15.8%
EPSS 15.8% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known

Summary

An exploitable use-after-free vulnerability exists in the JavaScript implementation of Nitro Pro PDF. A specially crafted document can cause an object containing the path to a document to be destroyed and then later reused, resulting in a use-after-free vulnerability, which can lead to code execution under the context of the application. An attacker can convince a user to open a document to trigger this vulnerability.

Exploit prediction

15.78% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1265 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • n/a Nitro Pro

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.