VulnerabilityPublished 12 Aug 2026Updated 6 Nov 2026

CVE-2026-68450: Linux kernel · btrfs: free mapping node on duplicate reloc root insert

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in b7c5b8e1d5f0779dfbabc3068b7ac0f12e53b3a8 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 17:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in b7c5b8e1d5f0779dfbabc3068b7ac0f12e53b3a8, ae0629ff9ccb836416ada129f4edc7efea6eaaad, 797dc567146c7e3c4f8d9680e4fbc76e0a6d9151 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 57a304cfd43b2b4a5b44b8f5dc026abb34183068, < b7c5b8e1d5f0779dfbabc3068b7ac0f12e53b3a8	Fixed in b7c5b8e1d5f0779dfbabc3068b7ac0f12e53b3a8
LinuxLinux	Affected ≥ 57a304cfd43b2b4a5b44b8f5dc026abb34183068, < ae0629ff9ccb836416ada129f4edc7efea6eaaad	Fixed in ae0629ff9ccb836416ada129f4edc7efea6eaaad
LinuxLinux	Affected ≥ 57a304cfd43b2b4a5b44b8f5dc026abb34183068, < 797dc567146c7e3c4f8d9680e4fbc76e0a6d9151	Fixed in 797dc567146c7e3c4f8d9680e4fbc76e0a6d9151
LinuxLinux	Affected ≥ 57a304cfd43b2b4a5b44b8f5dc026abb34183068, < 92bedc0455552b42ada1a1f42b0e3a8593cdfccc	Fixed in 92bedc0455552b42ada1a1f42b0e3a8593cdfccc
LinuxLinux	Affected ≥ 57a304cfd43b2b4a5b44b8f5dc026abb34183068, < 29d9746812d8b7c37d594f484e994fd552c3ec33	Fixed in 29d9746812d8b7c37d594f484e994fd552c3ec33
LinuxLinux	Affected ≥ 57a304cfd43b2b4a5b44b8f5dc026abb34183068, < 14a8be9428435ee17f17fae7991215c246b7fd43	Fixed in 14a8be9428435ee17f17fae7991215c246b7fd43

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: free mapping node on duplicate reloc root insert __add_reloc_root() allocates a mapping_node before inserting it into rc->reloc_root_tree. If rb_simple_insert() finds an existing entry, it returns the existing rb_node and leaves the newly allocated node unlinked. The error path then returns -EEXIST without freeing the new node. Since the node was never inserted into reloc_root_tree, the later cleanup in put_reloc_control() cannot find it either. Free the newly allocated node before returning -EEXIST. The callers currently assert that -EEXIST should not happen, so this is a defensive cleanup for an unexpected duplicate insert path. If the path is ever reached, the local allocation should still be released.

References

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