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TI-2021-04851 Aliases CVE-2021-21806GHSA-x2v5-56r3-vrw9

Use after free in Webkit

Priority MEDIUM 43CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 3 fixed, 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.3 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in remote code execution. The victim needs to visit a malicious web site to trigger the vulnerability.

Why it matters now

EPSS 0.02835 86th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 2 advisoriesRed Hat: 3 fixed, 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—WebkitWebkit WebKitGTK 2.30.3—No fix listedCNA
  • Webkit Vendor— Affected Webkit WebKitGTK 2.30.3 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:webkitgtk:webkitgtk:2.30.3:*:*:*:*:*:x64:*2.30.3VulnerableWebKitGTK
  • cpe:2.3:a:webkitgtk:webkitgtk:2.30.3:*:*:*:*:*:x64:* Versions 2.30.3 Vulnerable ·WebKitGTK

Remediation

Red Hat 2 advisories

  • RHSA-2025:10364 Released 2025-07-07 · Red Hat rating Important
    webkitgtk4 security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) webkitgtk4-2.48.3-2.el7_9, webkitgtk4-devel-2.48.3-2.el7_9, webkitgtk4-jsc-2.48.3-2.el7_9 +1
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) webkitgtk4-devel-2.48.3-2.el7_9, webkitgtk4-doc-2.48.3-2.el7_9, webkitgtk4-jsc-devel-2.48.3-2.el7_9
  • RHSA-2021:4381 Released 2021-11-09 · Red Hat rating Moderate
    GNOME security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) LibRaw-devel-0.19.5-3.el8
    • Red Hat Enterprise Linux AppStream (v. 8) LibRaw-0.19.5-3.el8, gnome-autoar-0.2.3-2.el8, webkit2gtk3-2.32.3-2.el8 +3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:4381
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2025:10364
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2025:10364
Not affected: 4 products
  • Red Hat CodeReady Linux Builder (v. 8)
  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux AppStream (v. 8)
  • Red Hat Enterprise Linux BaseOS (v. 8)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-21806
  2. 2026-10-03 Alias added: GHSA-x2v5-56r3-vrw9

References

Exploit 1

Advisory 1

  • TI-2021-01572 Apple iOS and iPadOS: A remote attacker may be able to cause arbitrary code execution KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-22512 Memory corruption in Apple Safari KEVCVSS 3.1HIGH 8.8
  • TI-2025-05957 Improper input validation in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2022-14420 Out-of-bounds write in Apple Safari KEVCVSS 3.1HIGH 8.8
  • TI-2022-02117 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2021-11319 Integer overflow in Apple watchOS KEVCVSS 3.1HIGH 8.8
See all 67 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences