CVE-2026-7531: Use-after-free in PQC hybrid key-share handling. This is an incomplete-fix follow-up to CVE-2026-5460 (released in 5.9.1): a malicious TLS 1.3 server sending a truncated PQC hybrid

criticalCVSS 9.8CVE-2026-7531

Use-after-free in PQC hybrid key-share handling. This is an incomplete-fix follow-up to CVE-2026-5460 (released in 5.9.1): a malicious TLS 1.3 server sending a truncated PQC hybrid KeyShare can still trigger the error cleanup path to operate on freed memory.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: critical — CVSS 9.8
Published: 2026-06-25
Last updated: 2026-06-26
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-7531

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-75310.35% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 27% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-7531	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

criticalCVE-2026-7531: Use-after-free in PQC hybrid key-share handlingmsrc

Recent advisories for Use-after-free in PQC

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

criticalCVE-2026-7531: Use-after-free in PQC hybrid key-share handlingmsrc · 2026-06-09