radvdump: Stack-based Buffer Overflow
CVE-2026-48715 is a high-severity stack-based buffer overflow vulnerability in radvdump from Radvd-project, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected radvdump versions: < 2.21. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.33% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Radvd to 2.21 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Radvd-project | radvdump | < 2.21 | Not stated |
| Radvd.litech | Radvd | before 2.21 | 2.21 |
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
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- 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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.7 | High | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
radvd is a router advertisement daemon for IPv6. Prior to version 2.21, the `radvdump` utility shipped with radvd contains a stack buffer overflow in the Route Information option parser. When processing a crafted ICMPv6 Router Advertisement, `print_ff()` copies up to 2032 bytes from attacker-controlled packet data into a 16-byte `struct in6_addr` on the stack, overflowing by up to 2016 bytes. Note that the main `radvd` daemon is not affected by the vulnerability. Version 2.21 patches the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Stack-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 8.6 High severity
- 8.8 High severity
- 8.2 High severity
- 9.1 Critical severity
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