CVE-2025-62409: envoyproxy envoy · NULL Pointer Dereference
Affects envoyproxy envoySource CVE Database V5
Not known to be exploited · CVSS 6.6 Medium : upgrade to 1.33.10 when convenient.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.33.10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UExploitation evidence
Disclosed: evidence found.
CVE published 16 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade envoyproxy/envoy to 1.33.10.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubenvoyproxy/envoypkg:github/envoyproxy/envoyOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
European organizations should immediately assess their Envoy proxy deployments to identify versions prior to 1.36.1, 1.35.5, 1.34.9, and 1.33.10. Upgrading to these patched versions is the most effective mitigation. Network administrators should implement strict ingress filtering and rate limiting to reduce the likelihood of large, malformed TCP requests triggering the vulnerability. Monitoring Envoy logs and metrics for unusual connection pool crashes or flow control anomalies can provide early detection of exploitation attempts. Employing redundancy and failover mechanisms for Envoy proxies can minimize service disruption if crashes occur. Organizations should also review their ALPN configurations to ensure they are up to date and consider isolating vulnerable proxy instances from critical network segments until patched. Regular vulnerability scanning and patch management processes should be enforced to prevent similar issues. Finally, maintaining an incident response plan for DoS events involving proxy infrastructure is recommended.
Description
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.