VulnerabilityPublished 18 Oct 2026

CVE-2026-98503: Linux kernel · packet: use ubuf_info completion for TX_RING packets

Source GCVE Database

Authoritative record:CVE-2026-98503· High

Not known to be exploited · fixed in eda9bcb721f15a93746a99eabda33d80b86404fd : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in eda9bcb721f15a93746a99eabda33d80b86404fd, e67c455d79fbf709a94965f09a2be6bf4f4ba5fd, 9518405613863d0bf0700927a21367f5942cf058 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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.

ghsa-mw3g-vwg9-8r8c

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=4.14.86 <4.15 >=4.19.7 <4.20	Fixed in eda9bcb721f15a93746a99eabda33d80b86404fd e67c455d79fbf709a94965f09a2be6bf4f4ba5fd 9518405613863d0bf0700927a21367f5942cf058 4.20 4.15 2a0c9afefc0ecea2cc30ccfbbbc98182a0986191
LinuxLinux	Affected =4.20	Fixed in–
Linuxlinux/kernel`pkg:rpm/linux/kernel`Other threats	Affected >=4.14.86 <4.15 >=4.19.7 <4.20 =4.20	Fixed in 4.15 4.20

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to address this vulnerability by adopting standard zerocopy completion and improving synchronization of ring slot release. Users should update to the patched kernel versions once available.

Description

A vulnerability in the Linux kernel's packet TX_RING handling was resolved by switching to a standard zerocopy completion mechanism to prevent premature reuse of ring slots. The issue involved skb->destructor being called early, causing ring slots to be reused while still linked to socket buffers, potentially leading to memory corruption or data integrity issues. The fix ensures slots are only released once all references to the payload are freed or copied, improving stability and correctness in packet transmission.

Impact

The vulnerability could lead to premature reuse of packet ring slots while still referenced by socket buffers, potentially causing memory corruption or data integrity issues in packet transmission. This may affect network stack stability and reliability. No confirmed exploits in the wild are known.

Summary

The Linux kernel vulnerability CVE-2026-98503 relates to the packet TX_RING implementation where skbs with fragments pointing into ring slots could have their slots prematurely released due to early invocation of skb->destructor via skb_orphan. This could cause reuse of slots still linked to skbs, risking memory corruption. The patch replaces the custom completion with the standard ubuf_info zerocopy completion callback, ensuring slots are released only after all references to the payload are cleared. Additional changes include per-packet allocation of tpacket_uarg to prevent aliasing in shared ring slots, and synchronization improvements using sk_wmem_alloc references to guarantee slot validity. The fix reverts obsolete infrastructure and depends on a prior commit deferring TX_RING free until skbs finish.

References

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