No exploitation reportedFix available

CVE-2021-32765

Q: Is CVE-2021-32765 actively exploited?

Active exploitation of CVE-2021-32765 has not been confirmed. Its EPSS score was 2.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-32765?

CVE-2021-32765 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-10-04
WeaknessCWE-190 · CWE-680

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

Hiredis is a minimalistic C client library for the Redis database. In affected versions Hiredis is vulnurable to integer overflow if provided maliciously crafted or corrupted `RESP` `mult-bulk` protocol data. When parsing `multi-bulk` (array-like) replies, hiredis fails to check if `count * sizeof(redisReply*)` can be represented in `SIZE_MAX`. If it can not, and the `calloc()` call doesn't itself make this check, it would result in a short allocation and subsequent buffer overflow. Users of hiredis who are unable to update may set the [maxelements](https://github.com/redis/hiredis#reader-max-array-elements) context option to a value small enough that no overflow is possible.

Timeline

dates in UTC

2021-10-0421:15CVE 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-2021-32765?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-32765?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Debian debian linux

Branch	Affected	Fixed in	Source
9.0	= 9.0	no fix published	NVD

Netapp management services for element software and netapp hci

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

Redis hiredis

Branch	Affected	Fixed in	Source
1.0	< 1.0.1	1.0.1	NVD

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

Fix

Advisories and patches

github.comPatch
github.comMitigation

Detection

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

Sources

CNACVSS 3.18.8read 2026-10-23
NVDCVSS 3.18.8read 2026-10-23
NVDCVSS 2.06.5read 2026-10-23
CNAweakness (CWE)CWE-190, CWE-680read 2026-10-23
NVDweakness (CWE)CWE-190read 2026-10-23
FIRST EPSSEPSS score2.1 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published: 2021-10-04
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-32765?

Is CVE-2021-32765 actively exploited?

Active exploitation of CVE-2021-32765 has not been confirmed. Its EPSS score was 2.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-32765?

CVE-2021-32765 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database