NFStream Local Denial of Service (DoS)

published 2021-02-16 5 y ago modified 2026-06-17 4 mo ago also GHSA-whmq-cfm5-j8mj , PYSEC-2021-68 , EUVD-2021-0146

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits: 0; none known

An issue was discovered in NFStream 5.2.0. Because some allocated modules are not correctly freed, if the nfstream object is directly destroyed without being used after it is created, it will cause a memory leak that may result in a local denial of service (DoS).

Patch / fix

fixed in 1

pypi nfstream 6.0.0

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/ntop/nDPI/issues/994 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	2.1	AV:L/AC:L/Au:N/C:N/I:N/A:P
GitHub	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
pypi	nfstream	1 listed version <6.0.0	6.0.0

Classification

Weakness

CWE-401 Missing Release of Memory after Effective Lifetime
CWE-770 Allocation of Resources Without Limits or Throttling

References

github.com /ntop/nDPI/issues/994
web, exploit, third-party-advisory, report
nvd.nist.gov /vuln/detail/CVE-2020-25340
advisory
github.com /nfstream/nfstream
package
github.com /pypa/advisory-database/tree/main/vulns/nfstream/PYSEC-2021-68.yaml
web
github.com /advisories/GHSA-whmq-cfm5-j8mj
advisory

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.

Summary