Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.
- Vendor
- Red Hat
- Product
- Polkit
- CVSS
- 7.8
- EPSS (exploit probability)
- 94.9%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-4034 being exploited?
Yes. CISA added CVE-2021-4034 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 94.9% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-23. Full cross-catalog view: /kev-comparison
CVE-2021-4034 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Red Hat CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-94218 Keycloak session enforcement bypass on policy upgradewrite-up | [ LOW ] | 3.1 | 0.3% | — |
| CVE-2026-94217 Keycloak UMA token endpoint resource ownership confusionwrite-up | [ LOW ] | 3.5 | 0.2% | — |
| CVE-2026-94215 Keycloak Admin REST API client cache flawwrite-up | [ MEDIUM ] | 5.5 | 0.3% | — |
| CVE-2026-94213 Keycloak authorization policy evaluation exposes permissionswrite-up | [ MEDIUM ] | 4.9 | 0.4% | — |
| CVE-2015-5287 Red Hat Automatic Bug Reporting Tool Privilege Escalation Vulnerability | [ MEDIUM ] | 6.9 | 5.0% | |
| CVE-2015-3246 Red Hat Libuser Race Condition Vulnerability | [ HIGH ] | 7.2 | 8.5% | |
| CVE-2018-14667 Red Hat JBoss RichFaces Framework Expression Language Injection Vulnerability | [ CRITICAL ] | 9.8 | 74.2% | |
| CVE-2021-3560 Red Hat Polkit Incorrect Authorization Vulnerability | [ HIGH ] | 7.8 | 23.7% |