Answer in brief
CVE-2026-63868 records a Medium severity (CVSS 5.5) vulnerability in net: garp: fix unsigned integer underflow in garp_pdu_parse_attr. 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 5.5. 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: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 |
| cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <29f28172afb2ae7b31e9bf3e978396f20b381688 || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <973cf7c433d27f4d9556d0b7c332543be7ed7a6e || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <d8dcd14aa886b8effd83022c550669f4f262854b || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <74e02121be1dcc0efcd56ebdf0171d6129105659 || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <04e22fefac1af3e32f245e9045382348773b5d59 || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <a11f1a671b1361f0f1278dc0041374f2730df73f || >=eca9ebac651f774d8b10fce7c5d173c3c3d3394f <16e408e607a94b646fb14a2a98422c6877ae4b3c | 29f28172afb2ae7b31e9bf3e978396f20b381688, 973cf7c433d27f4d9556d0b7c332543be7ed7a6e, d8dcd14aa886b8effd83022c550669f4f262854b, 74e02121be1dcc0efcd56ebdf0171d6129105659, d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a, 04e22fefac1af3e32f245e9045382348773b5d59, a11f1a671b1361f0f1278dc0041374f2730df73f, 16e408e607a94b646fb14a2a98422c6877ae4b3c |
| Linux/Linuxgeneric | 2.6.27 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
In the Linux kernel, the following vulnerability has been resolved: net: garp: fix unsigned integer underflow in garp_pdu_parse_attr The receive-side GARP attribute parser computes dlen with reversed operands: dlen = sizeof(*ga) - ga->len; ga->len is the on-wire attribute length and includes the GARP attribute header. For normal attributes with data, ga->len is larger than sizeof(*ga), so the subtraction underflows in unsigned arithmetic. The resulting value is later passed to garp_attr_lookup(), whose length argument is u8. After truncation, the parsed data length usually no longer matches the length stored for locally registered attributes, so received Join/Leave events are ignored. This breaks the GARP receive path for common attributes, such as GVRP VLAN registration attributes. Compute the data length as the attribute length minus the header length.
Quoted source text, attributed separately from HOL analysis.