What is CVE-2020-28852?

CVE-2020-28852 is a high-severity vulnerability in Golang Text, classified under Improper Validation of Array Index. CVSS score: 7.5/10. Published 2021-01-02.

How severe is CVE-2020-28852?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2020-28852 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Golang Text

CVE-2020-28852

In x/text in Go before v0.3.5, a "slice bounds out of range" panic occurs in language.ParseAcceptLanguage while processing a BCP 47 tag. (x/text/language is supposed to be able to parse an HTTP Accept-Language header.)

Published 2021-01-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.017 (76.9th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 76.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: +0.000

Affected products

Golang Text

Weakness classification (CWE)

CWE-129 — Improper Validation of Array Index

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

github.com/golang/go/issues/42536 (Exploit, Third Party Advisory, Issue Tracking)
security.netapp.com/advisory/ntap-20210212-0004/ (Third Party Advisory)

Frequently asked questions

What is CVE-2020-28852?: CVE-2020-28852 is a high-severity vulnerability in Golang Text, classified under Improper Validation of Array Index. CVSS score: 7.5/10. Published 2021-01-02.
How severe is CVE-2020-28852?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2020-28852 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.