How severe is CVE-2020-25866?

CVE-2020-25866 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-2020-25866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-25866?

CVE-2020-25866 primarily affects Wireshark. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-25866?

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-2020-25866 published?

CVE-2020-25866 was published on 2020-10-06 and last updated on 2026-06-17.

CVE-2020-25866

CVE-2020-25866 is a high-severity vulnerability in Wireshark 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-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Wireshark
Published: 2020-10-06
Last modified: 2026-06-17

Description

In Wireshark 3.2.0 to 3.2.6 and 3.0.0 to 3.0.13, the BLIP protocol dissector has a NULL pointer dereference because a buffer was sized for compressed (not uncompressed) messages. This was addressed in epan/dissectors/packet-blip.c by allowing reasonable compression ratios and rejecting ZIP bombs.

Frequently asked questions

What is CVE-2020-25866?: In Wireshark 3.2.0 to 3.2.6 and 3.0.0 to 3.0.13, the BLIP protocol dissector has a NULL pointer dereference because a buffer was sized for compressed (not uncompressed) messages. This was addressed in epan/dissectors/packet-blip.c by allowing reasonable compression ratios and rejecting ZIP bombs.
How severe is CVE-2020-25866?: CVE-2020-25866 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-2020-25866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-25866?: CVE-2020-25866 primarily affects Wireshark. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-25866?: 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-2020-25866 published?: CVE-2020-25866 was published on 2020-10-06 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*

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