CVE-2026-98287
pppoatm: ensure a writable skb header and linear data
No known exploitation. EPSS puts it in the 7th percentile. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- LinuxAffected: ≥ 4cf476ced45d7f12df30a68e833b263e7a2202d1, < 208ccc4d08b1897451e9ba01c016bf93ff107966Upgrade to: 208ccc4d08b1897451e9ba01c016bf93ff107966Affected: ≥ 4cf476ced45d7f12df30a68e833b263e7a2202d1, < e6cd1bba7d113c15c00ac63671213a096fe4d686Upgrade to: e6cd1bba7d113c15c00ac63671213a096fe4d686Affected: ≥ 4cf476ced45d7f12df30a68e833b263e7a2202d1, < ffc448eb54f5ba80d4212c1e870cdb92b0f709faUpgrade to: ffc448eb54f5ba80d4212c1e870cdb92b0f709faAffected: ≥ 4cf476ced45d7f12df30a68e833b263e7a2202d1, < 8e66c5969acd859ba72fb0a7fa895623fc1b3769Upgrade to: 8e66c5969acd859ba72fb0a7fa895623fc1b3769 + 3 more branchesStated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
In the Linux kernel, the following vulnerability has been resolved: pppoatm: ensure a writable skb header and linear data In pppoatm_send(), LLC encapsulation checks whether there is sufficient headroom for the 4-byte LLC header, but does not ensure that the skb header is writable. Normal transmit packets passing through ppp_start_xmit() have their header unshared via skb_cow_head(). However, packets can also reach pppoatm_send() via PPP channel bridging (PPPIOCBRIDGECHAN) without going through ppp_start_xmit(). Use skb_cow_head() to ensure both sufficient headroom and a writable header before pushing the LLC header. While at it: - Call pskb_may_pull(skb, 1) before inspecting skb->data[0] to prevent out-of-bounds reads on zero-length or non-linear frames (e.g. from bridging). - Defer SC_COMP_PROT protocol compression until after pppoatm_may_send() succeeds. This eliminates the temporary skb allocation on admission failure and completely removes the fragile "undo" heuristic at the nospace label, avoiding any risk of reading uninitialized headroom or performing an unbalanced skb_push().
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.2% chance of exploitation activity in the next 30 days, which ranks it in the 7th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
2 events over 0 days, from the signal feeds we watch.
- Publishedrecord updated
Affected products
Sources
References in the record
- git.kernel.org/stable/c/208ccc4d08b1897451e9ba01c016bf93ff107966
- git.kernel.org/stable/c/30992fe39e65589ed8e000425e088fa74994b811
- git.kernel.org/stable/c/8e66c5969acd859ba72fb0a7fa895623fc1b3769
And 4 more references. See all after sign-in
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