CVE-2026-64383: linux Double Free
Vulnerability summary
CVE-2026-64383 is a critical (CVSS 9.8) Double Free vulnerability in linux. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 31 · Related 27Timeline
- 25-07-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
0.00 pp
From 0.46% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu142 products
- linuxAll versions (No fix recorded) | < 6.8.0-147.147 | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1067.70 | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.12.96-1 | < 7.1.4-1
- linux-6.12< 6.12.100-1~deb12u1
Linux2 products
- linux≥ 433042a91f9373241307725b52de573933ffedbf, < 6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb | ≥ 4f1fffa2376922f3d1d506e49c0fd445b023a28e, < 878757163eea684750107a31ea134c103863515d | ≥ 4f1fffa2376922f3d1d506e49c0fd445b023a28e, < 3407240cde132a4b72d6429a2625a09a2f78adaf | ≥ 4f1fffa2376922f3d1d506e49c0fd445b023a28e, < 013a9a3da46c5dabcf18f65ea6a47874ba12a15d | ≥ 4f1fffa2376922f3d1d506e49c0fd445b023a28e, < 4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a | ≥ 6.6.32, < 6.6.145 | 6.8
- linux_kernelEOL≥ 6.6.32, < 6.6.145 | ≥ 6.8.1, < 6.12.96 | ≥ 6.13, < 6.18.39 | ≥ 6.19, < 7.1.4 | 6.8 | 6.8:rc2 | 6.8:rc3 | 6.8:rc4 | 6.8:rc5 | 6.8:rc6 | 6.8:rc7
3 vendors · 146 products