CVE-2026-66733
CVE-2026-66733 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-789.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v4: 8.7
- EPSS exploit prediction: 1% (57th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-789
- Published:
- Last modified:
Description
Sonic 3 A.I.R. before commit 2492d18 contains an unbounded memory allocation vulnerability in ReceivedPacketCache::enqueuePacket() that allows unauthenticated remote attackers to crash the server process by sending a crafted UDP packet with mUniquePacketID set to the maximum uint32 value. The mUniquePacketID field is read directly from the UDP wire-format packet header without bounds checking, causing the server to allocate one CacheItem per missing packet ID gap, exhausting available host memory and propagating an uncaught std::bad_alloc exception to std::terminate().
Frequently asked questions
- What is CVE-2026-66733?
- Sonic 3 A.I.R. before commit 2492d18 contains an unbounded memory allocation vulnerability in ReceivedPacketCache::enqueuePacket() that allows unauthenticated remote attackers to crash the server process by sending a crafted UDP packet with mUniquePacketID set to the maximum uint32 value. The mUniquePacketID field is read directly from the UDP wire-format packet header without bounds checking, causing the server to allocate one CacheItem per missing packet ID gap, exhausting available host memory and propagating an uncaught std::bad_alloc exception to std::terminate().
- How severe is CVE-2026-66733?
- CVE-2026-66733 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-66733 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-66733?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-66733 published?
- CVE-2026-66733 was published on 2026-08-06.
References
- https://github.com/Eukaryot/sonic3air/commit/2492d1882cd2cf1cc1d7415729ce5c4fd686cd4f
- https://www.vulncheck.com/advisories/sonic-3-a-i-r-unbounded-memory-allocation-dos-via-receivedpacketcache
Other CWE-789 vulnerabilities
- CVE-2021-34869 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop…
- CVE-2021-34868 — High (CVSS 8.8): This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop…
- CVE-2026-69219 — High (CVSS 8.7): The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes.…
- CVE-2026-58067 — High (CVSS 8.7): A vulnerability in Veeam Service Provider Console allowing an unauthenticated attacker to exhaust host memory and cause…
- CVE-2026-14682 — High (CVSS 8.7): In Bouncy Castle for Java before 1.85, Possible OOM from unbounded up-front allocation on a definite-length read. This…
- CVE-2026-12852 — High (CVSS 8.7): In Bouncy Castle for Java before 1.85, MLS wire decoder allocates attacker-declared opaque length before bounds check.