No exploitation reportedFix available

CVE-2020-28196

Q: Is CVE-2020-28196 actively exploited?

Active exploitation of CVE-2020-28196 has not been confirmed. Its EPSS score was 4.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-28196?

CVE-2020-28196 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2020-11-06
Fixed in1.18.3 · 1.17.2
WeaknessCWE-674

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

MIT Kerberos 5 (aka krb5) before 1.17.2 and 1.18.x before 1.18.3 allows unbounded recursion via an ASN.1-encoded Kerberos message because the lib/krb5/asn.1/asn1_encode.c support for BER indefinite lengths lacks a recursion limit.

Timeline

dates in UTC

2020-11-0608:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-28196?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-28196?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Mit kerberos 5

Branch	Affected	Fixed in	Source
1.18	≥ 1.18.0, < 1.18.3	1.18.3	NVD
1.17	< 1.17.2	1.17.2	NVD

Fedoraproject fedora

Branch	Affected	Fixed in	Source
31.x	= 31	no fix published	NVD

Netapp active iq unified manager

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

8 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Mit kerberos 5 to 1.18.3 · 1.17.2

Advisories and patches

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2025-12-03
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.17.52025-12-03
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CISA-ADPweakness (CWE)CWE-6742025-12-03
NVDweakness (CWE)CWE-674read 2026-10-23
FIRST EPSSEPSS score4.4 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2020-11-06
Last Modified: 2026-10-14
NVD status: Modified

Frequently asked questions

What is CVE-2020-28196?

Is CVE-2020-28196 actively exploited?

Active exploitation of CVE-2020-28196 has not been confirmed. Its EPSS score was 4.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-28196?

CVE-2020-28196 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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