CVE-2026-78659
published 2026-10-08CVE-2026-78659: When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server…
PriorityP344high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.63%
49.8th percentile
When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently.
Affected
27 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apache | thrift | — | — |
| buildah_project | buildah | — | — |
| confidential-containers | trustee | — | — |
| container-tools_rhel8 | buildah | — | — |
| container-tools_rhel8 | conmon | — | — |
| container-tools_rhel8 | containernetworking-plugins | — | — |
| container-tools_rhel8 | crun | — | — |
| container-tools_rhel8 | oci-seccomp-bpf-hook | — | — |
| container-tools_rhel8 | podman | — | — |
| container-tools_rhel8 | runc | — | — |
| container-tools_rhel8 | skopeo | — | — |
| container-tools_rhel8 | toolbox | — | — |
| etcd | etcd | — | — |
| git-lfs | git-lfs | — | — |
| go-toolset_rhel8 | golang | — | — |
| go_standard_library | net_http | < 1.26.9 | 1.26.9 |
| go_standard_library | net_http_internal_http2 | >= 1.27.0-0 < 1.27.2 | 1.27.2 |
| golang.org | x_net_golang.org_x_net_http2 | < 0.60.0 | 0.60.0 |
| grafana | grafana | — | — |
| helm | helm | — | — |
| inductiveautomation | ignition | — | — |
| kata-containers | kata-containers | — | — |
| kubernetes | cri-o | — | — |
| podman_project | podman | — | — |
| redhat | openshift | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.5HIGH
vendor_ubuntu7.5HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Ubuntu
Go vulnerabilities
vendor_ubuntu·2026-10-19·CVSS 7.5
CVE-2026-56866 [HIGH] Go vulnerabilities
Title: Go vulnerabilities
Summary: Several security issues were fixed in Go.
It was discovered that Go did not enforce a maximum recursion depth when
parsing deeply nested ASN.1 structures. An attacker could possibly use this
issue to cause Go to crash, resulting in a denial of service.
(CVE-2026-33818)
It was discovered that Go incorrectly reset the depth counter when decoding
XML elements. An attacker could possibly use this issue to cause Go to
crash via deeply nested XML input, resulting in a denial of service.
(CVE-2026-56859)
It was discovered that Go incorrectly handled TLS KeyUpdate messages after
the handshake was completed. A remote attacker could possibly use this
issue to cause Go to use excessive resources, leading to a denial of
service. (CVE-2026-56862)
It was discovere
Red Hat
net/http: golang.org/x/net/http2: golang: net/http: Denial of Service via HTTP/2 trailer header memory exhaustion
vendor_redhat·2026-10-08·CVSS 7.5
CVE-2026-78659 [HIGH] CWE-770 net/http: golang.org/x/net/http2: golang: net/http: Denial of Service via HTTP/2 trailer header memory exhaustion
net/http: golang.org/x/net/http2: golang: net/http: Denial of Service via HTTP/2 trailer header memory exhaustion
When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated d
VulDB
Go HTTP/2 Server amplification (EUVD-2026-95419)
vuldb·2026-10-09·CVSS 7.5
CVE-2026-78659 [HIGH] Go HTTP/2 Server amplification (EUVD-2026-95419)
A vulnerability has been found in Go and classified as problematic. Affected by this issue is some unknown functionality of the component HTTP2 Server. The manipulation leads to asymmetric resource consumption.
This vulnerability is documented as CVE-2026-78659. The attack can be initiated remotely. There is not any exploit available.
No detection rules found.
No public exploits indexed.
2026-10-08
Published