A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.
Conclusion & alert: CVE-2025-8671 is rated Moderate Risk (56.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.93%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-31 | 1.29% | 0.93% | -0.37% |
| 2 | 2026-05-30 | 1.20% | 1.29% | +0.10% |
| 3 | 2026-05-29 | — | 1.20% | — |
Full EPSS history (13 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2025-8671: 3 source package rows (dnsdist, lighttpd, varnish); 9 state rows across 6 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-community, edge-main); fixed 9, open 0. | https://security.alpinelinux.org/vuln/CVE-2025-8671 |
debian
|
unimportant | CVE-2025-8671 unimportant priority: Debian including 3 source packages (h2o, haproxy, varnish), 12 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 8, open 4. | https://security-tracker.debian.org/tracker/CVE-2025-8671 |
redhat
|
— | — | https://access.redhat.com/security/cve/CVE-2025-8671 |
suse
|
high | CVE-2025-8671 severity important: SUSE including 23 source package names (dnsdist-1.9.11-150700.3.6.1, dnsdist-1.9.11-160000.1.1, …), 27 product×package rows across 7 product lines (SUSE Linux Enterprise High Availability Extension 12 SP5, SUSE Linux Enterprise Module for Basesystem 15 SP7, … (7 product lines)): Fixed 24, Known Not Affected 2, First Fixed 1. | https://www.suse.com/security/cve/CVE-2025-8671/ |
ubuntu
|
medium | CVE-2025-8671 medium priority: Ubuntu including 5 source packages (dnsdist, h2o, haproxy, lighttpd, varnish), 40 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): needs-triage 20, not-affected 12, ignored 3, released 3, DNE 1, needed 1. | https://ubuntu.com/security/CVE-2025-8671 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||