Inverted size check in Linux ALSA OSS sequencer reads
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel ALSA OSS sequencer read path, from 2.6.12 before the fixed releases, has an inverted size check in snd_seq_oss_read(). The check stops when the next queued event is smaller than the remaining buffer, so events that fit are not copied and larger events can be copied into a smaller read. An undersized read can therefore look like end-of-file.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: oss: Reject reads that cannot fit the next event snd_seq_oss_read() checks whether the next queued OSS sequencer event fits in the remaining userspace buffer before removing it from the read queue. The check is inverted. It currently stops when the event is smaller than the remaining buffer, so a normal 4-byte event is not copied for an 8-byte read buffer. Conversely, an 8-byte event can be copied for a smaller read count. Break only when the remaining userspace buffer is smaller than the next event, and report -EINVAL if no complete event has been copied. This prevents an undersized read from looking like end-of-file while leaving the event queued for a later read with a large enough buffer.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53 or 7.2. Red Hat lists Red Hat Enterprise Linux 6 with no fix planned and Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8 and Red Hat OpenShift Container Platform 4 with plan none available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-23 Threatist record created from CVE-2026-98912
- 2026-10-23 Alias added: GHSA-c2vm-8x7j-h34j
- 2026-10-26 Fix available: Linux/Linux@0 · CNA
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/b3b4b647313757a275be7f7f9d0415d0a90acf73
- https://git.kernel.org/stable/c/591226398c1f93bd994678237ff0be229b19d3bb
- https://git.kernel.org/stable/c/372bec8a01e2ab8eaa6851bdc346ede5f82dba99
- https://git.kernel.org/stable/c/2922cf2583e590f51bed613a6fcd27b9aea83674
- https://git.kernel.org/stable/c/7483fd5f6990f43cc266e94b3f50ce84856ebb97
- https://git.kernel.org/stable/c/20b8520d1ef996173065f7abdde47b99136c0785
- https://git.kernel.org/stable/c/611f538253d970f4d152003841544e875828d015
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Sources
- CVE-2026-98912 · CVE Program
- CVE-2026-98912 · NVD
- FIRST EPSS
- GHSA-c2vm-8x7j-h34j · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98912 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences