NULL pointer dereference in Envoyproxy Envoy
CVE-2025-62409
Envoy is a cloud-native, open source edge and service proxy. Prior to 1.36.1, 1.35.5, 1.34.9, and 1.33.10, large requests and responses can potentially trigger TCP connection pool crashes due to flow control management in Envoy. It will happen when the connection is closing but upstream data is still coming, resulting in a buffer watermark callback nullptr reference. The vulnerability impacts TCP proxy and HTTP 1 & 2 mixed use cases based on ALPN. This vulnerability is fixed in 1.36.1, 1.35.5, 1.34.9, and 1.33.10.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (37.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.000
Affected products
- Envoyproxy Envoy — versions >= 1.34.0, < 1.34.9, < 1.33.10, 1.36.0
Weakness classification (CWE)
References
- github.com/envoyproxy/envoy/security/advisories/GHSA-pq33-4jxh-hgm3 (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-62409?
- CVE-2025-62409 is a high-severity vulnerability in Envoyproxy Envoy, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2025-10-16.
- How severe is CVE-2025-62409?
- High severity. CVSS v3 base score is 7.5 out of 10.