8.6

CVE-2025-40046: io_uring/zcrx: fix overshooting recv limit

Deferred
AliasesUBUNTU-CVE-2025-40046DEBIAN-CVE-2025-40046
Published 28-10-2025Last modified 05-08-2026

Vulnerability summary

CVE-2025-40046 is a high (CVSS 8.6) vulnerability in linux. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.5% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.6 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.35%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 7
OPENSUSE-SU-2025:15702-1OPENSUSE-SU-2026:10301-1USN-8029-1USN-8029-2USN-8029-3USN-8030-1

Timeline

  1. 28-10-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix overshooting recv limit It's reported that sometimes a zcrx request can receive more than was requested. It's caused by io_zcrx_recv_skb() adjusting desc->count for all received buffers including frag lists, but then doing recursive calls to process frag list skbs, which leads to desc->count double accounting and underflow.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.35%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.35% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu93 products
  • linux< 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.17.6-1
Linux1 product
  • linux≥ 6699ec9a23f85f1764183430209c741847c45f12, < 8bcc9eaf1b19f1a7029cba19f6bd4122b40f6c4f | ≥ 6699ec9a23f85f1764183430209c741847c45f12, < 09cfd3c52ea76f43b3cb15e570aeddf633d65e80 | 6.15

3 vendors · 95 products

References

11 links
Show all 11 references