CVE-2025-43434VulnerabilityPublished 4 Nov 2025Updated 2 Apr 2026

CVE-2025-43434: Processing maliciously crafted web content may lead to an unexpected Safari crash

Affects Apple SafariSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium · fixed in 26.1 : update Apple Safari when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.2% chance of exploitation in 30 days – higher than 69% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 26.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Apple Safari	Affected =0	Fixed in–

AI-suggested

To mitigate CVE-2025-43434, organizations should prioritize updating all Apple devices to Safari 26.1 or later and corresponding OS versions (iOS 18.7.2, iPadOS 18.7.2, macOS Tahoe 26.1, visionOS 26.1, watchOS 26.1). Enforce centralized patch management policies to ensure timely deployment of these updates. Implement web filtering solutions to block access to known malicious websites and employ DNS filtering to reduce exposure to crafted web content. Educate users about the risks of visiting untrusted websites and the importance of applying software updates promptly. For environments with critical systems using Safari, consider deploying endpoint protection that can detect abnormal browser crashes or memory corruption attempts. Monitor browser crash logs and network traffic for anomalies that might indicate exploitation attempts. Additionally, consider alternative browsers for high-risk users until patches are applied. Regularly review and update incident response plans to address potential denial-of-service scenarios caused by browser instability.

Description

A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.1, iOS 18.7.2 and iPadOS 18.7.2, iOS 26.1 and iPadOS 26.1, macOS Tahoe 26.1, visionOS 26.1, watchOS 26.1. Processing maliciously crafted web content may lead to an unexpected Safari crash.

Impact

The primary impact of CVE-2025-43434 is denial of service due to unexpected Safari crashes when processing malicious web content. For organizations, this can disrupt business operations, especially those relying on Safari for web-based applications or internal portals. While the vulnerability does not expose confidential data or allow integrity breaches, repeated crashes could degrade user productivity and potentially be leveraged in targeted denial-of-service campaigns. Automated systems or kiosks using Safari might be particularly vulnerable to service interruptions. The lack of known exploits reduces immediate risk, but the ease of triggering a crash via crafted web content means attackers could weaponize this flaw in phishing or watering-hole attacks. Organizations with large Apple device deployments, especially in sectors like finance, healthcare, or government, could face operational impacts if users are directed to malicious sites. The vulnerability’s medium severity reflects limited impact scope but non-negligible availability concerns.

CWE-416Use After Free (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #7
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Architecture and Design · Language Selection
Choose a language that provides automatic memory management.
Implementation · Attack Surface Reduction
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Apr 2026, 02:21 UTC

WeaknessesCWE-416

Technical details

References

Community reviews

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