CVE-2026-73500
etcd: `tlsListener.acceptLoop` spawns unbounded handshake goroutines with no deadline
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.5.33, 3.6.14, and 3.7.1, a network attacker who can reach an etcd TLS listener can open many TCP connections and never send a ClientHello. In client/pkg/transport/listener_tls.go, each connection handled by tlsListener.acceptLoop spawns a goroutine that blocks indefinitely inside tls.Conn.Handshake() and remains tracked in the pending map. Unbounded goroutine and map growth can exhaust memory in the etcd process, causing loss of availability for the cluster and, when etcd backs Kubernetes, the control plane. This issue is fixed in versions 3.5.33, 3.6.14, and 3.7.1.
Timeline
ID reserved
By GitHub_M
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | High8.7 | 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 |
| NVDNVD · Awaiting Analysis | 4.0 | High8.7 | 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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.40% · top 66% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogo.etcd.io/etcd/v3GHSA-6vch-q96h-7gc3 (opens in a new tab)
References (9)
- https://github.com/etcd-io/etcd/security/advisories/GHSA-6vch-q96h-7gc3 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/etcd-io/etcd/pull/22130 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/2e07efce9745004eb4773cffaada9b5cdf77cff2 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/89ff6d50796049d4f1136915ba21504b76e7e372 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/8e4dd0679a2c6b095d2a32a749fda2521c7809a3 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/commit/f73cba7d920019f91a1ea1f6697833e42731f057 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/releases/tag/v3.5.33 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/releases/tag/v3.6.14 (opens in a new tab)x_refsource_MISC
- https://github.com/etcd-io/etcd/releases/tag/v3.7.1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-6vch-q96h-7gc3 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-73500)Record last updated .