No exploitation reportedFix available

CVE-2021-22156

Q: Is CVE-2021-22156 actively exploited?

Active exploitation of CVE-2021-22156 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-22156?

CVE-2021-22156 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-08-17
Fixed in6.5.0
WeaknessCWE-190

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

An integer overflow vulnerability in the calloc() function of the C runtime library of affected versions of BlackBerry® QNX Software Development Platform (SDP) version(s) 6.5.0SP1 and earlier, QNX OS for Medical 1.1 and earlier, and QNX OS for Safety 1.0.1 and earlier that could allow an attacker to potentially perform a denial of service or execute arbitrary code.

Timeline

dates in UTC

2021-08-1719:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 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-2021-22156?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-22156?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Blackberry qnx software development platform

Branch	Affected	Fixed in	Source
6.5	< 6.5.0	6.5.0	NVD
6.5	= 6.5.0	no fix published	NVD

Blackberry qnx os for medical

Branch	Affected	Fixed in	Source
1.1	≤ 1.1.1	no fix published	NVD

Blackberry qnx os for safety

Branch	Affected	Fixed in	Source
1.0	≤ 1.0.2	no fix published	NVD

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

Fix

Update Blackberry qnx software development platform to 6.5.0

Advisories and patches

support.blackberry.comPatch · Vendor Advisory

Detection

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

Sources

CNACVSS 3.19read 2026-10-23
NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.06.8read 2026-10-23
CNAweakness (CWE)CWE-190read 2026-10-23
NVDweakness (CWE)CWE-190read 2026-10-23
FIRST EPSSEPSS score1.8 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2021-08-17
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-22156?

Is CVE-2021-22156 actively exploited?

Active exploitation of CVE-2021-22156 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-22156?

CVE-2021-22156 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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