VulnerabilityPublished 6 Oct 2026Updated 19 Oct 2026

CVE-2026-98257: Linux kernel · rds: ib: use rds_conn_drop() on protocol version mismatch

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in f97d8c7bab7843631206a114986c9059da03efeb : 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: 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in f97d8c7bab7843631206a114986c9059da03efeb, d392b16acd0908f077289aad8bba066ff16de336, b5c9f2951d330d4a198a64d6e60f79b4bd6ef078 +5

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 6 Oct 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 ≥ f147dd9ecabf23fd63d2562ffe64252a0453ecde, < f97d8c7bab7843631206a114986c9059da03efeb	Fixed in f97d8c7bab7843631206a114986c9059da03efeb
LinuxLinux	Affected ≥ f147dd9ecabf23fd63d2562ffe64252a0453ecde, < d392b16acd0908f077289aad8bba066ff16de336	Fixed in d392b16acd0908f077289aad8bba066ff16de336
LinuxLinux	Affected ≥ f147dd9ecabf23fd63d2562ffe64252a0453ecde, < b5c9f2951d330d4a198a64d6e60f79b4bd6ef078	Fixed in b5c9f2951d330d4a198a64d6e60f79b4bd6ef078
LinuxLinux	Affected ≥ f147dd9ecabf23fd63d2562ffe64252a0453ecde, < 424019be3f637da76b74f44a40034669acbb166f	Fixed in 424019be3f637da76b74f44a40034669acbb166f
LinuxLinux	Affected ≥ f147dd9ecabf23fd63d2562ffe64252a0453ecde, < 344c72a0bc2703a6de4918ed935850e07dae3af2	Fixed in 344c72a0bc2703a6de4918ed935850e07dae3af2
LinuxLinux	Affected ≥ f147dd9ecabf23fd63d2562ffe64252a0453ecde, < 65ca0a5037152a5a80b8fe6aac80eb80458be573	Fixed in 65ca0a5037152a5a80b8fe6aac80eb80458be573

AI-suggested

A fix is available in the Linux kernel as indicated by the presence of fixed commit versions. Users and administrators should update to a Linux kernel version that includes these fixes. No other mitigation or workaround is indicated or required.

Description

CVE-2026-98257 is a vulnerability in the Linux kernel's RDS over InfiniBand (rds: ib) implementation. It involves improper handling of protocol version mismatches during RDMA-CM event processing, leading to a deadlock that stalls RDS connection workqueues. This occurs because the connection destruction function is called synchronously while holding a lock needed by shutdown work, causing a circular wait. The issue has been fixed by changing the code to use an asynchronous connection drop function instead.

Impact

The vulnerability causes a deadlock in the RDS connection workqueues, effectively stalling them. This results in a denial of service (DoS) condition affecting the availability of the RDS over InfiniBand functionality in the Linux kernel. There is no impact on confidentiality or integrity. The CVSS v3.1 score is 7.5 (high severity) with network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality or integrity impact, and high availability impact.

Summary

The vulnerability occurs in the Linux kernel's rds_ib_cm_connect_complete() function, which handles RDMA-CM events with a lock held (conn->c_cm_lock). When a peer negotiates a protocol version older than RDS_PROTOCOL_COMPAT_VERSION, the handler previously called rds_conn_destroy(), which synchronously tears down the connection and flushes shutdown work requiring cp_cm_lock. Since cp_cm_lock is held by the event handler, this causes a deadlock between the flush and the shutdown work. Other failure paths use rds_conn_drop(), which marks the connection as errored and schedules shutdown work asynchronously, avoiding deadlock. The fix applies this asynchronous approach to the protocol version mismatch case as well.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:00 UTC

Technical details

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