Ladybird: Missing Synchronization
CVE-2025-47154 is a critical-severity missing synchronization vulnerability in Ladybird, with a CVSS 3.1 base score of 9.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version f5a670421954fc7130c3685b713c621b29516669 as the first without the flaw, so updating Ladybird to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.69% chance of exploitation within 30 days, higher than 53% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Ladybird to f5a670421954fc7130c3685b713c621b29516669 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Ladybird | Ladybird | before f5a670421954fc7130c3685b713c621b29516669 | f5a670421954fc7130c3685b713c621b29516669 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (mitre.org).
Official description
LibJS in Ladybird before f5a6704 mishandles the freeing of the vector that arguments_list references, leading to a use-after-free, and allowing remote attackers to execute arbitrary code via a crafted .js file. NOTE: the GitHub README says "Ladybird is in a pre-alpha state, and only suitable for use by developers."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Synchronization
The product utilizes a shared resource in a concurrent manner but does not attempt to synchronize access to the resource.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Missing Synchronization vulnerabilities
- 7.5 High severity
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