ALSA: seq: Clear variable event pointer on read
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 5 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Clear variable event pointer on read snd_seq_read() copies a queued variable-length event header to userspace before expanding the payload. Queued variable-length events use SNDRV_SEQ_EXT_CHAINED internally, and data.ext.ptr points at the first extension cell. The read side strips SNDRV_SEQ_EXT_* bits from data.ext.len before the copy, but it leaves data.ext.ptr untouched. A userspace sequencer client can therefore write a direct variable event to itself and read back the extension-cell kernel address from the returned header. Clear the temporary header pointer before copy_to_user(). The original queued event remains unchanged and is still passed to snd_seq_expand_var_event(), so payload expansion keeps using the internal chain.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.12 and later | 5.10.273, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.12 and later Fixed in 5.10.273, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 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 10 | Affected | No fix yet: Fix deferred |
| 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 Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-74339
- 2026-10-03 Alias added: GHSA-5rp2-cp2v-9mcx
- 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@8a631e1aaa1ebbc9de916927fa01707244e18291 · CNA
- 2026-10-30 1 new reference · CNA
- 2026-11-06 CISA SSVC decision points changed
References
Other 8
- https://git.kernel.org/stable/c/8a631e1aaa1ebbc9de916927fa01707244e18291
- https://git.kernel.org/stable/c/14fe4f75fd5309d6b75f8e840ada88912b374207
- https://git.kernel.org/stable/c/f29243c211928114f8b906e0a3fee77c236f14c8
- https://git.kernel.org/stable/c/e0c3edd86414534cfd179fefe45b38c29c01ae7a
- https://git.kernel.org/stable/c/6b52211eba213c461f68922708a99d8190c1fcd5
- https://git.kernel.org/stable/c/74ac1ce1f4afdb3b80b6742fa28fb86c8c51d31b
- https://git.kernel.org/stable/c/c2ac9287e89916da684c2a548798351e63eb59ee
- https://git.kernel.org/stable/c/705dd6dcbc0ea87351c660c1a6443f85f1001c76
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Sources
- CVE-2026-74339 · CVE Program
- CVE-2026-74339 · NVD
- FIRST EPSS
- GHSA-5rp2-cp2v-9mcx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74339 · 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