VulnerabilityPublished 11 Sep 2026Updated 21 Oct 2026

CVE-2026-89680: Linux kernel · nfsd: fix nfsd_file leak on inter-server COPY setup failure

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in ab949252fdf102ae74329a0caa7995a849d0dafa : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in ab949252fdf102ae74329a0caa7995a849d0dafa, 424d5c95108a4809b832cb0a312c61de4aec0078, 88a76145451d703eedd867b5989bf73d17340399 +2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 ≥ ce0887ac96d35c7105090e166bb0807dc0a0e838, < ab949252fdf102ae74329a0caa7995a849d0dafa	Fixed in ab949252fdf102ae74329a0caa7995a849d0dafa
LinuxLinux	Affected ≥ ce0887ac96d35c7105090e166bb0807dc0a0e838, < 424d5c95108a4809b832cb0a312c61de4aec0078	Fixed in 424d5c95108a4809b832cb0a312c61de4aec0078
LinuxLinux	Affected ≥ ce0887ac96d35c7105090e166bb0807dc0a0e838, < 88a76145451d703eedd867b5989bf73d17340399	Fixed in 88a76145451d703eedd867b5989bf73d17340399
LinuxLinux	Affected ≥ ce0887ac96d35c7105090e166bb0807dc0a0e838, < 6ed8d6de7ec90c4ba84eb82673058f506e5777fd	Fixed in 6ed8d6de7ec90c4ba84eb82673058f506e5777fd
LinuxLinux	Affected ≥ ce0887ac96d35c7105090e166bb0807dc0a0e838, < 1a6a41b848455bf6ba2c9da2dfb0730e608ce7ab	Fixed in 1a6a41b848455bf6ba2c9da2dfb0730e608ce7ab
LinuxLinux	Affected =5.6	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix nfsd_file leak on inter-server COPY setup failure When nfsd4_setup_inter_ssc() fails, nfsd4_copy() returns nfserr_offload_denied directly, bypassing the out: label where release_copy_files() would drop the nf_dst reference taken by nfs4_preprocess_stateid_op(). Each failed inter-server COPY leaks one nfsd_file, pinning file/inode/dentry/vfsmount. Fix by setting status and jumping to out: instead of returning directly.

References

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