7.5

CVE-2026-53395: nfsd: fix dead ACL conflict guard in nfsd4_create

Analyzed
AliasesUBUNTU-CVE-2026-53395DEBIAN-CVE-2026-53395
Published 19-07-2026Last modified 17-08-2026

Vulnerability summary

CVE-2026-53395 is a high (CVSS 7.5) Uncontrolled Recursion vulnerability in linux. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 42% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (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
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.49%
0%100%
Low · +0.11 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 12 · Related 12
OPENSUSE-SU-2026:11339-1USN-8726-1USN-8726-2USN-8726-3USN-8726-4USN-8727-1

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr().

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.49%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

Increase +0.11 pp

From 0.38% 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

Affected systems

Version check

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

Ubuntu112 products
  • linux< 7.0.0-31.31
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 7.0.0-1012.12
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ d2ca50606f5f0235d7780c1cd73b6614a5d07620, < 8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e | ≥ d2ca50606f5f0235d7780c1cd73b6614a5d07620, < a60f25a800846ab8e5a13f8a9d05111f2aee55a7 | 7.0
  • linux_kernel≥ 7.0, < 7.1.3
Debian1 product
  • linux< 7.1.3-1

3 vendors · 115 products

References

17 links
Show all 17 references