Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and…
Priority MEDIUM 47CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.
Summary
Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02709 86th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:thekelleys:dnsmasq:2.86:*:*:*:*:*:*:* | 2.86 | Vulnerable | Thekelleys |
- cpe:2.3:a:thekelleys:dnsmasq:2.86:*:*:*:*:*:*:* Versions 2.86 Vulnerable ·Thekelleys
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Not affected: 5 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenStack Platform 13 (Queens)
Timeline
- 2026-10-02 Threatist record created from CVE-2021-45952
- 2026-10-03 Alias added: GHSA-h2ww-p8c6-6v58
References
More Thekelleys Dnsmasq vulnerabilities
- TI-2017-10595 Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a… CVSS 3.0CRITICAL 9.8
- TI-2023-27571 Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related… CVSS 3.1HIGH 7.5
- TI-2017-10596 Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a… CVSS 3.0CRITICAL 9.8
- TI-2017-10594 Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a… CVSS 3.1CRITICAL 9.8
- TI-2021-20958 Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from… CVSS 3.1CRITICAL 9.8
- TI-2020-15697 Heap-based buffer overflow in dnsmasq CVSS 3.1HIGH 8.1
Sources
- CVE-2021-45952 · CVE Program
- CVE-2021-45952 · NVD
- FIRST EPSS
- GHSA-h2ww-p8c6-6v58 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-45952 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences