CVE-2026-80977

HIGHCVSS 7.8/10EPSS 0.13%

Last modified

CVE-2026-80977 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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. EPSS estimates a 0.13% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.13%

2.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < 6493165034bca14033bf49c9cec7b45e97a91497; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < b4452349dcf4d561e13be768d5d278de58248930; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < 363c4252ffc473a0203e91b83ede5519dfb8bd07; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < 6ec22afc82a3cae07ade0a6ec361ae2532128ff5; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < 15aa81b390d401abf4b8211042470e9e92e3b7fb; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < 288f9970670841044ab030104fa6b6ed159949d0; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < 0370da114a9bc044e248b85c6809d1b5e0c1f7f9; >= 25121173f7b1e4ac3fc692df6e7b8c52ec36abba, < f66bdb1cc0fcd227a062378f8be0b5873aa5600a
LinuxLinux3.8

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-80977?
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.
How severe is CVE-2026-80977?
CVE-2026-80977 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.13% probability of exploitation in the next 30 days.
How do I fix CVE-2026-80977?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST