CVE-2026-48521
Envoy: HTTP/3 connection pool selection null-derefs in ProdClusterManagerFactory::allocateConnPool when transport_socket_options is null
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
5.9
Envoy: HTTP/3 connection pool selection null-derefs in ProdClusterManagerFactory::allocateConnPool when transport_socket_options is null
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
- Record
CVE-2026-48521- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
EUVDEUVD-2026-84109
5.9
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
- Record
EUVD-2026-84109- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
NVD
5.9
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
- Record
CVE-2026-48521- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
OSV
5.9
Envoy: HTTP/3 connection pool selection null-derefs in ProdClusterManagerFactory::allocateConnPool when transport_socket_options is null
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
- Record
CVE-2026-48521- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
OSVBIT-envoy-2026-48521 No score
Envoy: HTTP/3 connection pool selection null-derefs in ProdClusterManagerFactory::allocateConnPool when transport_socket_options is null
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's ProdClusterManagerFactory::allocateConnPool dereferences transport_socket_options while selecting an HTTP/3 connection pool without first checking whether the pointer is null. LoadBalancerContext implementations used by synthetic, mirror, health-check, and async-client calls can return no transport-socket options. With auto_config and HTTP/3 enabled, routine traffic reaching one of those contexts can crash an Envoy worker. The relevant scope boundary is that the affected branch requires HTTP/3 in the protocol set and a context that supplies no transport-socket options. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
- Record
BIT-envoy-2026-48521- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11630-1 No score
istioctl-1.30.4-1.1 on GA media
These are all security issues fixed in the istioctl-1.30.4-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11630-1- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-48521 is a medium vulnerability (CVSS 5.9) in Envoyproxy Envoy, published August 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.74%, the 54th percentile. Fixed in envoy 1.36.10.
References
github.com/envoyproxy/envoy/security/advisories/GHSA-5vff-j9p4-38j3
github.com/envoyproxy/envoy/commit/8ef2da8527fcd17388b046c1add4fb47fb5d0868
github.com/envoyproxy/envoy/commit/cec4899acf03cf551f28611a5f32385648d95f96
github.com/envoyproxy/envoy/commit/e7b4839beef7f43594ce8e94c4563c80db04a8a7
github.com/envoyproxy/envoy/commit/f5436f44103fb14cb8ba42a8db0f54a06c98c45a
github.com/envoyproxy/envoy/releases/tag/v1.36.10
Show 18 moreShow less
github.com/envoyproxy/envoy/releases/tag/v1.37.6
github.com/envoyproxy/envoy/releases/tag/v1.38.4
github.com/envoyproxy/envoy/releases/tag/v1.39.1
nvd.nist.gov/vuln/detail/CVE-2026-48521
github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48521.json
suse.com/security/cve/CVE-2026-48521
suse.com/security/cve/CVE-2026-50572
suse.com/security/cve/CVE-2026-73511
suse.com/security/cve/CVE-2026-73512
suse.com/security/cve/CVE-2026-73513
suse.com/security/cve/CVE-2026-73546
suse.com/security/cve/CVE-2026-73547
suse.com/security/cve/CVE-2026-73548
suse.com/security/cve/CVE-2026-73549
suse.com/security/cve/CVE-2026-73550
suse.com/security/cve/CVE-2026-73551
suse.com/security/cve/CVE-2026-73552
suse.com/security/cve/CVE-2026-73553