VulnerabilityPublished 26 Oct 2026Updated 27 Oct 2026

CVE-2026-99000: Linux kernel · drm/xe: Fix shrinker accounting double-subtraction on nested external pins

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-99000· Medium

Not known to be exploited.

Data as of 28 Oct 2026, 01:59 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 23 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

Affected software

Product	Affected	Fixed in
Ubuntu 26.10linux`pkg:deb/ubuntu/linux?arch=source&distro=stonking`Other threats	Affected 7.0.0-14.14 – 7.3.0-9.9 6 affected builds	Fixed in–
Ubuntu 26.10linux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1003.3 5 affected builds	Fixed in–
Ubuntu 26.10linux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1003.3 5 affected builds	Fixed in–
Ubuntu 26.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonking`Other threats	Affected =7.0.0-1004.4 =7.3.0-1002.3 =7.3.0-1003.4	Fixed in–
Ubuntu 26.10linux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=stonking`Other threats	Affected 7.0.0-1003.3 – 7.3.0-1003.3 5 affected builds	Fixed in–
Ubuntu 26.10linux-oracle`pkg:deb/ubuntu/linux-oracle?arch=source&distro=stonking`Other threats	Affected 7.0.0-1003.3 – 7.3.0-1003.3 5 affected builds	Fixed in–

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

AI-suggested

A fix is available that corrects the accounting logic to update shrinker counts only on the outermost pin and final unpin, and excludes imported dma-bufs from shrinker accounting. Users should apply the updated Linux kernel versions containing this patch to resolve the issue. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's drm/xe subsystem causes incorrect shrinker accounting due to double-subtraction on nested external pins. This leads to underflow in the shrinker's page and object counts, potentially causing excessive invocation of the shrinker under memory pressure. The issue arises because nested pins subtract pages multiple times and nested unpins add them back prematurely. The fix ensures accounting updates only occur on the outermost pin and final unpin, and excludes imported dma-bufs from accounting to prevent underflows.

Impact

The vulnerability causes the shrinker's page and object counts to underflow due to double subtraction and addition in nested pin scenarios, leading to an inflated shrinkable page count. This can cause the shrinker to be invoked excessively under memory pressure, potentially degrading system performance or stability. There is no indication of direct code execution or privilege escalation. No known exploits in the wild have been reported.

Summary

The Linux kernel's drm/xe component mishandles shrinker accounting for external buffer object (BO) pins when nested pins occur. The functions xe_bo_pin_external() and xe_bo_unpin_external() support nested pins, but the accounting calls to xe_ttm_tt_account_subtract() and xe_ttm_tt_account_add() are invoked unconditionally on every pin/unpin call rather than only on transitions into and out of the pinned state. This causes the shrinker's page and object counts to become desynchronized, with underflows turning into large shrinkable page counts, triggering excessive shrinker activity under memory pressure. Additionally, imported dma-bufs were improperly accounted for, causing further underflows. The patch centralizes accounting logic to update counts only on the outermost pin and final unpin, and excludes imported dma-bufs from accounting, resolving the underflow and excessive shrinker invocation issues.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2026, 01:59 UTC

Technical details

References

Community reviews

Related threats