Kernel-stack disclosure via uninitialized console control header
Published Oct 18, 2026 · Updated Oct 18, 2026
Information disclosure in Linux's VCC driver allows guest OS users to receive kernel stack bytes via console control packets. In drivers/tty/vcc.c, vcc_send_ctl() leaves pkt.tag.stype_env uninitialized and transmits the header through ldc_write(). Exposure requires a Sun LDOM VCC connection and receipt of a control packet at the peer endpoint; the disclosed data is residual stack content, not an arbitrary-address read.
Summary
What happened
Information disclosure in Linux's VCC driver allows guest OS users to receive kernel stack bytes via console control packets. In drivers/tty/vcc.c, vcc_send_ctl() leaves pkt.tag.stype_env uninitialized and transmits the header through ldc_write(). Exposure requires a Sun LDOM VCC connection and receipt of a control packet at the peer endpoint; the disclosed data is residual stack content, not an arbitrary-address read.
The record
- CVE
- CVE-2026-98755
- Published
- Oct 18, 2026
- Updated
- Oct 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Oct 18, 2026CVE publishedPublication date reported by the CVE source.
- Oct 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.12.113
- Affected versionversion=0 <6.18.56
- Affected versionversion=0 <7.2.10
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1f71f565e3585da1098ff19ca3c24687dab59185
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <399aa38af1d78001612e3130b2056ea392a355ca
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4335278d0e75395cbfaf71c84b521df56d69e936
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6f1a08ef02825b440126c406ea63ef6128888e15
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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