CVE-2026-12707

HIGHPre-NVD 7.57.5
EchelonGraph scoreLOW confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Summary

Cloudflare quiche was discovered to be vulnerable to memory resource exhaustion due to unbounded queuing of post-handshake client migration events.

Impact

quiche supports the connection migration features described in Section 9 of RFC 9000, which allows a single QUIC connection to survive changes in the network path. Although quiche implements the protections described in Section 9.3 of RFC 9000 to limit server state commitment, it was discovered that the collection of PathEvents, intended to be consumed by applications via the path_event_next() function, was not bounded.

Once the QUIC handshake completed, a peer could exploit rapid source address migration in order to cause unbounded queuing of the PathEvent::ReusedSourceConnectionId type. Servers are vulnerable even if active connection migration is disabled.

Mitigation:

*

Applications can call path_event_next() to drain the PathEvent collection, mitigating the attack.

*

Users are requested to upgrade to quiche 0.29.3 which is the earliest version that prevents excessive queueing of PathEvent::ReusedSourceConnectionId.

CVSS v3
7.5
EG Score
7.5(low)
EPSS
16.5%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 14, 2026

Advisory Details (1)

Auto-updated Jul 14, 2026
Patch available. Sources: github.
github Patch Available

Unbounded path event queue growth via peer-driven source connection ID rotation · Advisory · cloudflare/quiche · GitHub

https://github.com/cloudflare/quiche/security/advisories/GHSA-4q5x-gp38-rfp4

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× in last 7d / 5× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:46 UTCEG score recompute
  3. 2026-07-15 04:14 UTCEG score recompute
  4. 2026-07-14 15:42 UTCEG score recompute
  5. 2026-07-14 15:40 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-12707?
CVE-2026-12707 is a high vulnerability published on July 14, 2026. Summary Cloudflare quiche was discovered to be vulnerable to memory resource exhaustion due to unbounded queuing of post-handshake client migration events. Impact quiche supports the connection migration features described in Section 9 of RFC 9000, which allows a single QUIC connection to survive…
When was CVE-2026-12707 disclosed?
CVE-2026-12707 was first published in the National Vulnerability Database on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12707 actively exploited?
CVE-2026-12707 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12707?
CVE-2026-12707 has a CVSS v3 base score of 7.5 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-12707?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12707, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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