Answer in brief
CVE-2026-90054 records a Unknown severity vulnerability in tcp: fix corruption of urgent data on multi-segment retransmit. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=10d3be569243def8d92ac3722395ef5a59c504e6 <8eb51013b6308870479a64b4a2a018697b997849 || >=10d3be569243def8d92ac3722395ef5a59c504e6 <711bfd762bec05fb19bc3b17cbb157c39f4e66da || >=10d3be569243def8d92ac3722395ef5a59c504e6 <3d4e005c198dc410ad568f832bffa7569c059ff8 || >=10d3be569243def8d92ac3722395ef5a59c504e6 <4fd2ee4ac154c204d95d8db72221446dac5af9b8 || >=10d3be569243def8d92ac3722395ef5a59c504e6 <ebe55406404f3cb28e36d2b668e2c6c05026ec29 || >=10d3be569243def8d92ac3722395ef5a59c504e6 <b8f08a94b2a4addc39249dcf9c792e786108621b || >=10d3be569243def8d92ac3722395ef5a59c504e6 <47eb90299e6882d6445672530dd7c51ac33ebdbd || >=10d3be569243def8d92ac3722395ef5a59c504e6 <ce2b807f42ed5e55567b8864ab72963f90779270 | 8eb51013b6308870479a64b4a2a018697b997849, 711bfd762bec05fb19bc3b17cbb157c39f4e66da, 3d4e005c198dc410ad568f832bffa7569c059ff8, 4fd2ee4ac154c204d95d8db72221446dac5af9b8, ebe55406404f3cb28e36d2b668e2c6c05026ec29, b8f08a94b2a4addc39249dcf9c792e786108621b, 47eb90299e6882d6445672530dd7c51ac33ebdbd, ce2b807f42ed5e55567b8864ab72963f90779270 |
| Linux/Linuxgeneric | 4.7 | Not reported |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: fix corruption of urgent data on multi-segment retransmit On the normal xmit path, while in urgent mode we refuse to build a multi-segment TSO packet, so every segment gets its own urg_ptr: /* tcp_write_xmit() */ limit = mss_now; if (tso_segs > 1 && !tcp_urg_mode(tp)) limit = tcp_mss_split_point(...); The retransmit path has no such guard. __tcp_retransmit_skb() builds a segs > 1 skb and hands it to the GSO layer, which only advances th->seq per segment and copies urg_ptr verbatim: /* __tcp_retransmit_skb() */ len = cur_mss * segs; /* segs > 1, no urg_mode check */ ... /* tcp_gso_segment(): bumps seq only, urg_ptr is copied */ urg_ptr is an offset from the segment's own seq, so a copied value points at a different place on each segment. The receiver rebuilds the absolute urgent seq as seg.seq + urg_ptr, so it walks a moving urgent point instead of the one OOB byte: seg1 seq 1 urg_ptr 5001 -> urgent @ 5001 (ok) seg2 seq 1001 urg_ptr 5001 -> urgent @ 6001 (wrong, +MSS) seg3 seq 2001 urg_ptr 5001 -> urgent @ 7001 (wrong, +2*MSS) The real OOB byte is never pointed at, so the receiver stops splicing it out and delivers it as normal in-band data, corrupting the stream. Guard the retransmit length like the xmit path: keep segs = 1 while in urgent mode.
Quoted source text, attributed separately from HOL analysis.