CVE-2026-64577
In the Linux kernel, the following vulnerability has been resolved: gtp: check skb_pull_data() return in gtp1u_send_echo_resp() gtp1u_send_echo_resp() ignores skb_pull_data()'s return value. Its caller gtp1u_udp_encap_recv() only guarantees 16 bytes (udphdr + gtp1_header), but the pull requests 20 (gtp1_header_long + udphdr). For a 16-19 byte echo request the pull fails and returns NULL without advancing skb->data; execution continues, and the following skb_push() plus the IP header pushed by iptunnel_xmit() move skb->data below skb->head, tripping skb_under_panic(). Fix it by dropping the packet when skb_pull_data() fails. skbuff: skb_under_panic: ... kernel BUG at net/core/skbuff.c:214! Call Trace: skb_push (net/core/skbuff.c:2648) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:82) gtp_encap_recv (drivers/net/gtp.c:701 drivers/net/gtp.c:808 drivers/net/gtp.c:920) udp_queue_rcv_one_skb (net/ipv4/udp.c:2388) ... Kernel panic - not syncing: Fatal exception in interrupt
Affected versions
Linux kernel versions
5.18
and later are affected. Fixed in
6.6.148,
6.12.101,
6.18.42,
7.1.6,
7.2-rc5
and their respective stable series.
References
5 totalFrequently asked questions
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What is CVE-2026-64577?
CVE-2026-64577 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18 onward and has been patched in 6.6.148, 6.12.101, 6.18.42 and others. CVE-2026-64577 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-64577?
Yes. CVE-2026-64577 has been patched. Fixed versions include 6.6.148, 6.12.101, 6.18.42 and others. If you are running Linux kernel 5.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-64577 actively exploited?
No. CVE-2026-64577 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.