CVE-2026-52935
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
In the Linux kernel's xfrm/espintcp module, a vulnerability was found where the partial send state (ctx->partial) is reused before completion. The espintcp_sendmsg() function may overwrite an active send state, leading to a stale offset in a new message and a potential out-of-bounds memory read.
Risk Assessment
The organization faces a memory safety bug that could cause an out-of-bounds read in kernel memory, potentially leading to data leakage or system crash.
Recommendation
Immediately update the Linux kernel to a version containing the fix that prevents reuse of the partial send state in espintcp before it completes.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: xfrm: espintcp: do not reuse an in-progress partial send espintcp keeps a single in-flight transmit in ctx->partial. Before building a new sk_msg, espintcp_sendmsg() first tries to flush that state through espintcp_push_msgs(). For blocking callers, espintcp_push_msgs() may return success even when the previous partial send is still pending. espintcp_sendmsg() would then reinitialize emsg->skmsg and reuse ctx->partial while the old transfer still owns that state. Do not rebuild the send message when ctx->partial is still in progress. If espintcp_push_msgs() returns with emsg->len still set, fail the new send instead of overwriting the live partial state. This is a memory-safety fix: reusing the live partial-send state can leave a stale offset attached to a new sk_msg and lead to an out-of- bounds read in the send path. tcp_sendmsg_locked() already handles waiting for send buffer memory, so the fix here is just to preserve espintcp's one-message-at-a-time transmit state.