High severity · published Sep 11, 2026
CVE-2026-80977
net: skbuff: don't touch shared zerocopy state in skb_tx_error()
7.8
CVSS
0.1%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: don't touch shared zerocopy state in skb_tx_error()
skb_tx_error() completes the zerocopy uarg and clears
SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears
SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone
shares, while the caller only owns the reference it is about to drop.
Through a clone it tells the producer its pages are free and drops
SKBFL_SHARED_FRAG for an skb that is still in flight.
Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC:
clone_execute() sends a skb_clone() into ovs_dp_process_packet() while
do_execute_actions() keeps forwarding the original, and skb_clone()
does not privatise the frags here -- skb_orphan_frags() returns early
on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker
from the packet still being forwarded, and a later local ESP delivery
decrypts in place over frags it does not own privately.
Skip it for a cloned skb. Nothing is lost: skb_release_data() clears
the zerocopy state once the last reference to the shared data goes.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
25121173f7b1e4ac3fc692df6e7b8c52ec36abba before 6493165034bca14033bf49c9cec7b45e97a91497; 25121173f7b1e4ac3fc692df6e7b8c52ec36abba before b4452349dcf4d561e13be768d5d278de58248930; 25121173f7b1e4ac3fc692df6e7b8c52ec36abba before 363c4252ffc473a0203e91b83ede5519dfb8bd07; 25121173f7b1e4ac3fc692df6e7b8c52ec36abba before 6ec22afc82a3cae07ade0a6ec361ae2532128ff5; 25121173f7b1e4ac3fc692df6e7b8c52ec36abba before 15aa81b390d401abf4b8211042470e9e92e3b7fb; 25121173f7b1e4ac3fc692df6e7b8c52ec36abba before 288f9970670841044ab030104fa6b6ed159949d0; +3 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-80977
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-80977
git.kernel.org
https://git.kernel.org/stable/c/0370da114a9bc044e248b85c6809d1b5e0c1f7f9
git.kernel.org
https://git.kernel.org/stable/c/15aa81b390d401abf4b8211042470e9e92e3b7fb
git.kernel.org
https://git.kernel.org/stable/c/288f9970670841044ab030104fa6b6ed159949d0
git.kernel.org
https://git.kernel.org/stable/c/363c4252ffc473a0203e91b83ede5519dfb8bd07
git.kernel.org
https://git.kernel.org/stable/c/6493165034bca14033bf49c9cec7b45e97a91497
git.kernel.org
https://git.kernel.org/stable/c/6ec22afc82a3cae07ade0a6ec361ae2532128ff5
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