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NVD / CVE Program· CNA Linux

CVE-2026-97952: sunvdc: unmap LDC cookies when the descriptor send fails

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 0c6da21fa35e03fc74f09895433ccd6d4a9c3530, 24564576be423f3b5d7e67cd7df848ac66646497, 4.10; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0c6da21fa35e03fc74f09895433ccd6d4a9c3530, 24564576be423f3b5d7e67cd7df848ac66646497, 4.10; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: sunvdc: unmap LDC cookies when the descriptor send fails __send_request() maps the request's pages into the LDC channel's map table (ldc_map_sg()), fills in the descriptor and marks it VIO_DESC_READY before ringing the doorbell via __vdc_tx_trigger(). When the trigger fails, the error path only prints a message: the descriptor stays READY and the cookies are never unmapped. The mapping is normally released in vdc_end_one() when the peer completes the descriptor - but a descriptor whose doorbell was never sent will never complete, and since dr->prod is not advanced on failure, the reset path (vdc_requeue_inflight(), which walks [cons, prod)) never visits it either. The map table entries are leaked permanently. Since commit a11f6ca9aef9 ("sunvdc: Do not spin in an infinite loop when vio_ldc_send() returns EAGAIN") trigger failures occur in practice under load, so every resulting I/O error also leaks one request's worth of entries from the fixed-size (8192 entries per channel) map table. Because the allocator hands out contiguous ranges, fragmentation makes large multi-segment requests fail first as the table drains, until ldc_map_sg() fails permanently and the disk is dead until reboot. It also makes any retry-based recovery unusable: requeuing the request on -EAGAIN remaps the pages on every attempt, overwriting desc->cookies and orphaning the previous mapping, so the table drains at the retry rate. This is the memory exhaustion observed when the requeue approach was first tested in October 2025. Roll back on failure: unmap the cookies, mark the descriptor FREE again and clear the request entry. If the trigger failed with -ENOTCONN, __vdc_tx_trigger() has already reset the port, which tears down and reallocates both the dring and the LDC channel including its map table - nothing to roll back, and the stale descriptor must not be touched.

—No exploit Fix available
Published
Sep 25, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 627e656239c63d8a81672d08de7885e89c12fa75, a1ef7d5da9b2c145f811a80bb8197df6037a7572, 7ab4b6526fdcdfa7772984bbcd2ac4fd14fa223b, 3fbba4e55051d01a72b56ea192064175924bf56a, 3e380fc2ae4d18210eec9c472b12e2b2544f7dc1, 5.0affected
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before eb9c5f6747fe98b83c78cb5476a914e91d50e8e8affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before 24564576be423f3b5d7e67cd7df848ac66646497affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before 9251573e7cf7d797ae4a30b2a236af8242237a61affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before b0de6463667e9bb9dc14a83a9c24c1b6b3f7b5f7affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before ab81a5c1014a38dab0fb402609fd866b0bcb4726affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before 57835952566f0be9b365a6eb3a70b397a9d5ef47affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before f3322baa3a8ac87730feae952c1146269d78e098affected · git
    • a11f6ca9aef989b56cd31ff4ee2af4fb31a172ec and later · before 0c6da21fa35e03fc74f09895433ccd6d4a9c3530affected · git
    • 4.4.175 and later · before 4.5affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.7-17.2.7-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-97950Sep 25, 2026 · configfs: pin the symlink target's dirent instead of chasing ->ci_dentry
    0Monitor
  • ← EarlierCVE-2026-97951Sep 25, 2026 · scsi: target: iscsi: Fix hang for aborted WRITE_PENDING commands
    0Monitor
  • Later →CVE-2026-97953Sep 25, 2026 · net: stmmac: fix TX descriptor availability check for TSO traffic
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0c6da21fa35e03fc74f09895433ccd6d4a9c3530Vendor (CNA)
Linux Linux24564576be423f3b5d7e67cd7df848ac66646497Vendor (CNA)
Linux Linux4.10Vendor (CNA)
Linux Linux4.15Vendor (CNA)
Linux Linux4.20Vendor (CNA)
Linux Linux4.21Vendor (CNA)
Linux Linux4.5Vendor (CNA)
Linux Linux57835952566f0be9b365a6eb3a70b397a9d5ef47Vendor (CNA)
Linux Linux9251573e7cf7d797ae4a30b2a236af8242237a61Vendor (CNA)
Linux Linuxab81a5c1014a38dab0fb402609fd866b0bcb4726Vendor (CNA)
Linux Linuxb0de6463667e9bb9dc14a83a9c24c1b6b3f7b5f7Vendor (CNA)
Linux Linuxeb9c5f6747fe98b83c78cb5476a914e91d50e8e8Vendor (CNA)
Linux Linuxf3322baa3a8ac87730feae952c1146269d78e098Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records