9.8

CVE-2026-64534: linux

CVSS: 9.8v3.1CriticalReceived
AliasesUBUNTU-CVE-2026-64534DEBIAN-CVE-2026-64534
Published 27-07-2026Last modified 16-10-2026
Open JSON

Vulnerability summary

CVE-2026-64534 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.7% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.42%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 26 · Related 20
MGASA-2026-0336MGASA-2026-0337OPENSUSE-SU-2026:21910-1RHSA-2026:70402RHSA-2026:70403RHSA-2026:70498

Timeline

  1. 27-07-2026
    PublishedVulnerability first disclosed.
  2. 16-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected, nvmet_req_uninit() is called unconditionally. However, if the command arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init() had returned false and percpu_ref_tryget_live() was never executed. The unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a refcount underflow, leading to a WARNING in percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and eventually a permanent workqueue deadlock. Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling nvmet_req_uninit(), matching the existing pattern in nvmet_tcp_execute_request().

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

0.00 pp

From 0.42% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-34.34
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1013.13
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.180-1 | < 6.12.100-1 | < 7.1.3-1
  • linux-6.12< 6.12.100-1~deb12u1
Linux1 product
  • linux≥ 91edfca6f8b364d60cde3ddefaf7d03ddf35774b, < 22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf | ≥ fda871c0ba5d2eed2cd1c881573168129da70058, < ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e | ≥ fda871c0ba5d2eed2cd1c881573168129da70058, < c7874dad84b20433c0fe3919f291a762d40de08b | ≥ fda871c0ba5d2eed2cd1c881573168129da70058, < e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1 | ≥ fda871c0ba5d2eed2cd1c881573168129da70058, < d306da8833e75f669d93424fd84940236f3850bc | ≥ fda871c0ba5d2eed2cd1c881573168129da70058, < 2ed3c9d955e8cd6361f130623baa664a75fb345f | ≥ fda871c0ba5d2eed2cd1c881573168129da70058, < 4606467a75cfc16721937272ed29462a750b60c8 | 4b17476d809273617d3317fa0d4ae78aa488d760 | ≥ 5.10.20, < 5.10.261 | ≥ 5.11.3, < 5.12 | 5.12

3 vendors · 160 products

References

27 links
Show all 27 references