CVE-2026-49422Use-after-free in TCP RACK stack option handler
- 8.4HighCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
The RACK setsockopt(2) handler drops the connection lock in order to copy option data from userspace, then reacquires the lock. After reacquiring, it verifies that the TCP stack had not been switched away, but did not reload its pointer to the stack's per-connection control block. If userspace switches stacks twice during this window, the check will succeed but the saved pointer will refer to freed memory. The bug may be exploitable by an unprivileged local user to escalate privileges.
Timeline
ID reserved
By freebsd
- 3 months later
· 3 months later
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 |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | High8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.4.
Affected products
References
References1
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)
- EUVD EUVD-2026-62244 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-49422)Record last updated .