Answer in brief
CVE-2026-63912 records a Critical severity (CVSS 9.8) vulnerability in xfrm: esp: restore combined single-frag length gate. 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.
CVSS is 9.8. 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.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.18:-:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.18:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.18:rc5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.18:rc6:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.18:rc7:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=c075c3ea031757f8ea2d34567565b61a868c08d5 <566295735530ee513326049b0540f32ec050bf2e || >=a583f2f3c8788bffd7fd7baeb76bd6d80543d7ea <5d7ab86e2b6bc23054616bf6ac562013bf60af8c || >=5bd8baab087dff657e05387aee802e70304cc813 <36519e3d941fc99d3b52c134dbaf311f987a4708 || >=5bd8baab087dff657e05387aee802e70304cc813 <322e48187e0245ab2fff6fec2220b0cae677dbec || >=5bd8baab087dff657e05387aee802e70304cc813 <b84091ceddc9f133229dceab3ccc930bf27f9cba || >=5bd8baab087dff657e05387aee802e70304cc813 <c093468aea8277f77272a4f199b2e15e19cabb59 || >=5bd8baab087dff657e05387aee802e70304cc813 <65f3b3fc2347b89fe21db1e92c7681368415f095 || >=5bd8baab087dff657e05387aee802e70304cc813 <dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40 || 2c66b0c95bb0aa7652ba1eba293d0d5993b35a38 || ef6f83df1209a7d9bd1c605a62457d4c00f9179e || 3defefd22ad5fbbe639b6157fb7e6311b2bf333d || b657030870bb5351c5b1e84d4e9f186da6ca0496 || >=5.10.113 <5.10.259 || >=5.15.36 <5.15.210 || >=4.14.288 <4.15 || >=4.19.252 <4.20 || >=5.4.205 <5.5 || >=5.17.5 <5.18 | 566295735530ee513326049b0540f32ec050bf2e, 5d7ab86e2b6bc23054616bf6ac562013bf60af8c, 36519e3d941fc99d3b52c134dbaf311f987a4708, 322e48187e0245ab2fff6fec2220b0cae677dbec, b84091ceddc9f133229dceab3ccc930bf27f9cba, c093468aea8277f77272a4f199b2e15e19cabb59, 65f3b3fc2347b89fe21db1e92c7681368415f095, dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40, 5.10.259, 5.15.210, 4.15, 4.20, 5.5, 5.18 |
| Linux/Linuxgeneric | 5.18 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: restore combined single-frag length gate The ESP out-of-place fast path appends the trailer in esp_output_head() before esp_output_tail() allocates the destination page frag. The head-side gate currently checks skb->data_len and tailen separately, but the tail code allocates a single destination frag from the combined post-trailer skb->data_len. Reject the page-frag fast path when the combined aligned length exceeds a page. Otherwise skb_page_frag_refill() may fall back to a single page while the destination sg still spans the combined skb->data_len. Restore this combined-length page gate for both IPv4 and IPv6.
Quoted source text, attributed separately from HOL analysis.