CVE-2023-28204
Apple Safari / WebKit · Browsers and web engines
Apple Multiple Products WebKit Out-of-Bounds Read Vulnerability
At a glance
Exploited. Added to CISA’s catalog of exploited vulnerabilities on May 22, 2023.
Affected product: Apple Safari / WebKit (category Browsers and web engines, indicative classification). Name in CISA’s catalog: Apple Multiple Products.
What should I do?
Apply the security update from Apple.
Deadline set by CISA for US federal agencies: 21 days (due June 12, 2023). It only binds those agencies, but it is a useful measure of urgency.
- Apple security advisories page (general page, not the advisory for this vulnerability)
- The vendor’s specific advisory is listed in the NVD references: CVE-2023-28204 on the NVD website.
Original text of the required action (CISA)
Apply updates per vendor instructions.
Timeline
- Exploitation confirmed Added to CISA’s KEV catalog
- CISA deadline Remediation deadline set for US federal agencies
- Vulnerability published Publication date (NVD)
The facts, with their sources
- Exploitation confirmed
- Yes, on May 22, 2023 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Ransomware
- No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Hunt for compromise
- Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CISA required action
- Apply the security update from Apple. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CISA deadline
- June 12, 2023, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Vulnerability published
- June 23, 2023 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
- Product according to CISA
- Apple Multiple Products Filed by this site under “Browsers and web engines” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Severity and activity
FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.
Description
An out-of-bounds read was addressed with improved input validation. This issue is fixed in watchOS 9.5, tvOS 16.5, macOS Ventura 13.4, iOS 15.7.6 and iPadOS 15.7.6, Safari 16.5, iOS 16.5 and iPadOS 16.5. Processing web content may disclose sensitive information. Apple is aware of a report that this issue may have been actively exploited.
Official description from the NVD, collected Sep 29, 2026. CVE® description © The MITRE Corporation.
Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit contain an out-of-bounds read vulnerability that may disclose sensitive information when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.
Summary from CISA (KEV catalog).
CERT-FR advisories
No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.
Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.
Sources for this page
- CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
- NVD (NIST): CVSS severity, publication date, description, vendor references.
- EPSS (FIRST): probability of exploitation.
- CERT-FR: advisories and alerts (in French).
- Brand and category: indicative classification by this site (method).