How severe is CVE-2021-44540?

CVE-2021-44540 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-44540 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-44540?

CVE-2021-44540 affects Privoxy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-44540?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-44540 published?

CVE-2021-44540 was published on 2021-12-23 and last updated on 2026-06-17.

CVE-2021-44540

CVE-2021-44540 is a high-severity vulnerability in Privoxy with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-401
Affected product: Privoxy
Published: 2021-12-23
Last modified: 2026-06-17

Description

A vulnerability was found in Privoxy which was fixed in get_url_spec_param() by freeing memory of compiled pattern spec before bailing.

Frequently asked questions

What is CVE-2021-44540?: A vulnerability was found in Privoxy which was fixed in get_url_spec_param() by freeing memory of compiled pattern spec before bailing.
How severe is CVE-2021-44540?: CVE-2021-44540 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-44540 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-44540?: CVE-2021-44540 affects Privoxy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-44540?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-44540 published?: CVE-2021-44540 was published on 2021-12-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:privoxy:privoxy:*:*:*:*:*:*:*:*

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