In the Linux kernel, the following vulnerability has been resolved:
ppp_synctty: ensure a writeable skb header
ppp_sync_txmunge() checks headroom before prepending the address and
control bytes, but does not ensure that the skb header is writable.
A received skb can reach this function through PPP channel bridging
without passing through ppp_start_xmit(), which calls skb_cow_head().
For example, a PPPoE frame may share its buffer with a clone queued to
an AF_PACKET socket. If it is bridged to a synchronous tty channel, the
address/control bytes can overwrite data still visible to that socket.
Use skb_cow_head() to ensure both sufficient headroom and a writable
header.
ppp_synctty: ensure a writeable skb header
ppp_sync_txmunge() checks headroom before prepending the address and
control bytes, but does not ensure that the skb header is writable.
A received skb can reach this function through PPP channel bridging
without passing through ppp_start_xmit(), which calls skb_cow_head().
For example, a PPPoE frame may share its buffer with a clone queued to
an AF_PACKET socket. If it is bridged to a synchronous tty channel, the
address/control bytes can overwrite data still visible to that socket.
Use skb_cow_head() to ensure both sufficient headroom and a writable
header.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4817-1 | linux-6.12 security update |
Debian DLA |
DLA-4841-1 | linux security update |
Debian DSA |
DSA-6528-1 | linux security update |
Ubuntu USN |
USN-8961-1 | Linux kernel vulnerabilities |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sat, 03 Oct 2026 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Thu, 01 Oct 2026 05:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-119 |
Wed, 30 Sep 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-787 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 25 Sep 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-119 |
Fri, 25 Sep 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ppp_synctty: ensure a writeable skb header ppp_sync_txmunge() checks headroom before prepending the address and control bytes, but does not ensure that the skb header is writable. A received skb can reach this function through PPP channel bridging without passing through ppp_start_xmit(), which calls skb_cow_head(). For example, a PPPoE frame may share its buffer with a clone queued to an AF_PACKET socket. If it is bridged to a synchronous tty channel, the address/control bytes can overwrite data still visible to that socket. Use skb_cow_head() to ensure both sufficient headroom and a writable header. | |
| Title | ppp_synctty: ensure a writeable skb header | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-19T09:11:30.152Z
Reserved: 2026-09-25T10:18:58.206Z
Link: CVE-2026-97964
No data.
Status : Received
Published: 2026-09-25T11:17:24.187
Modified: 2026-10-19T10:17:47.790
Link: CVE-2026-97964
OpenCVE Enrichment
Updated: 2026-10-01T07:30:02Z
Weaknesses
Debian DLA
Debian DSA
Ubuntu USN