Answer in brief
CVE-2026-23243 records a High severity (CVSS 7.8) vulnerability in RDMA/umad: Reject negative data_len in ib_umad_write. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-23243 records a High severity (CVSS 7.8) vulnerability in RDMA/umad: Reject negative data_len in ib_umad_write. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. 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 7.8. 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), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2be8e3ee8efd6f99ce454115c29d09750915021a <1371ef6b1ecf3676b8942f5dfb3634fb0648128e || >=2be8e3ee8efd6f99ce454115c29d09750915021a <362e45fd9069ffa1523f9f1633b606ebf72060d7 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <6eb2919474ca105c5b13d19574e25f0ddcf19ca2 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d || >=2be8e3ee8efd6f99ce454115c29d09750915021a <9c80d688f402539dfc8f336de1380d6b4ee14316 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <205955f29c26330b1dc7fdeadd5bb97c38e26f56 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b || >=2be8e3ee8efd6f99ce454115c29d09750915021a <5551b02fdbfd85a325bb857f3a8f9c9f33397ed2 | 1371ef6b1ecf3676b8942f5dfb3634fb0648128e, 362e45fd9069ffa1523f9f1633b606ebf72060d7, 6eb2919474ca105c5b13d19574e25f0ddcf19ca2, a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d, 9c80d688f402539dfc8f336de1380d6b4ee14316, 205955f29c26330b1dc7fdeadd5bb97c38e26f56, 52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b, 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2 |
| Linux/Linuxgeneric | 2.6.24 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Mar 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: RDMA/umad: Reject negative data_len in ib_umad_write ib_umad_write computes data_len from user-controlled count and the MAD header sizes. With a mismatched user MAD header size and RMPP header length, data_len can become negative and reach ib_create_send_mad(). This can make the padding calculation exceed the segment size and trigger an out-of-bounds memset in alloc_send_rmpp_list(). Add an explicit check to reject negative data_len before creating the send buffer. KASAN splat: [ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0 [ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102 [ 211.365867] ib_create_send_mad+0xa01/0x11b0 [ 211.365887] ib_umad_write+0x853/0x1c80
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.8. 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), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2be8e3ee8efd6f99ce454115c29d09750915021a <1371ef6b1ecf3676b8942f5dfb3634fb0648128e || >=2be8e3ee8efd6f99ce454115c29d09750915021a <362e45fd9069ffa1523f9f1633b606ebf72060d7 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <6eb2919474ca105c5b13d19574e25f0ddcf19ca2 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d || >=2be8e3ee8efd6f99ce454115c29d09750915021a <9c80d688f402539dfc8f336de1380d6b4ee14316 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <205955f29c26330b1dc7fdeadd5bb97c38e26f56 || >=2be8e3ee8efd6f99ce454115c29d09750915021a <52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b || >=2be8e3ee8efd6f99ce454115c29d09750915021a <5551b02fdbfd85a325bb857f3a8f9c9f33397ed2 | 1371ef6b1ecf3676b8942f5dfb3634fb0648128e, 362e45fd9069ffa1523f9f1633b606ebf72060d7, 6eb2919474ca105c5b13d19574e25f0ddcf19ca2, a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d, 9c80d688f402539dfc8f336de1380d6b4ee14316, 205955f29c26330b1dc7fdeadd5bb97c38e26f56, 52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b, 5551b02fdbfd85a325bb857f3a8f9c9f33397ed2 |
| Linux/Linuxgeneric | 2.6.24 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Mar 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
In the Linux kernel, the following vulnerability has been resolved: RDMA/umad: Reject negative data_len in ib_umad_write ib_umad_write computes data_len from user-controlled count and the MAD header sizes. With a mismatched user MAD header size and RMPP header length, data_len can become negative and reach ib_create_send_mad(). This can make the padding calculation exceed the segment size and trigger an out-of-bounds memset in alloc_send_rmpp_list(). Add an explicit check to reject negative data_len before creating the send buffer. KASAN splat: [ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0 [ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102 [ 211.365867] ib_create_send_mad+0xa01/0x11b0 [ 211.365887] ib_umad_write+0x853/0x1c80
Quoted source text, attributed separately from HOL analysis.