CVE-2026-99270tcp: Fix potential UAF in reqsk_timer_handler().
- 8.1HighCVSS base score
- 0.40%Exploitation in 30 daysEPSS · top 65% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: Fix potential UAF in reqsk_timer_handler(). When TCP socket migration fails at inet_ehash_insert() in reqsk_timer_handler(), we jump to the no_ownership: label and free the new reqsk immediately with __reqsk_free(). Thus, we must stop the new reqsk's timer before jumping to the label, but the timer might be missed since the cited commit, resulting in UAF. As we are in the original reqsk's timer context, we can safely call timer_delete_sync() for the new reqsk. Let's pass false to __inet_csk_reqsk_queue_drop() to stop the new reqsk's timer.
Timeline
ID reserved
By Linux
- 39 days later
· 39 days later
Published
- 7 days later
· 7 days 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 |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.40% · top 65% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af – < f7fba81b00699360f96ed7d9a47b8c801e74c6f9
- affected 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af – < b3b56e95f6fad7fa7281450b443e861d82616fdb
- affected 83fccfc3940c4a2db90fd7e7079f5b465cd8c6af – < 97c8a3c1f73d828de43a5a88e8a9a143efb2b661
- affected d3a1196bfc462943694623412d8e03aaf172bdc1
- affected 4.1.11 – < 4.2
- affected 4.2
- unaffected < 4.2
- unaffected 6.12.117 – ≤ 6.12.*
- unaffected 6.18.61 – ≤ 6.18.*
- unaffected 7.1 – ≤ *
References
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-2026-115811 (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-2026-99270)Record last updated .