7.8

CVE-2026-93798: btrfs: fix reloc root cleanup in merge_reloc_roots()

Received
AliasesUBUNTU-CVE-2026-93798DEBIAN-CVE-2026-93798
Published 24-09-2026Last modified 03-10-2026

Vulnerability summary

CVE-2026-93798 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.13%
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 5 · Related 5
OPENSUSE-SU-2026:22167-1SUSE-SU-2026:24386-1SUSE-SU-2026:24422-1SUSE-SU-2026:24437-1SUSE-SU-2026:24446-1

Timeline

  1. 24-09-2026
    PublishedVulnerability first disclosed.
  2. 03-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix reloc root cleanup in merge_reloc_roots() If the root we got has zero root refs in its root item, we are resetting the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's correct (see the Link tag below). Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless the root points to the reloc root we have. Fix this by using clear_reloc_root(), which issues the memory barrier after setting the root's ->reloc_root to NULL and before clearing the bit BTRFS_ROOT_DEAD_RELOC_TREE from the root.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.13% 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: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu169 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linuxAll versions (No fix recorded) | < 6.1.190-1 | < 6.12.111-1 | < 7.2.6-1
  • linux-6.12< 6.12.111-1~deb12u1
Linux1 product
  • linux≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < 29531470b1bf1e8bd2df4941fe913106edbca615 | ≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < 415f8665a969d3c906e4fd7c90fcbb4b357886f6 | ≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < ee695a968aa73b1e67ccbf2133dc0e54381d32b2 | ≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < 0bc25f0a2d1b3e0a691431c4d7aef36afcd527c5 | ≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < ab48583aa9948205ff9a6470e23dbff74c565e24 | ≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < 63d6b1f04cd91c825329712aa526215ffa5d11ca | ≥ 1dae7e0e58b484eaa43d530f211098fdeeb0f404, < b78fe9563e2d5ae47805f1e5dc722c91fd30e1f8 | ee08663380ffd5a45a1c87580fbc305e8413c235 | 33823378ff2b510fd7b566f25bb18438aeb9b23b | ≥ 5.4.54, < 5.5 | ≥ 5.7.11, < 5.8 | 5.8

3 vendors · 172 products

References

10 links