Answer in brief
CVE-2026-53306 records a Medium severity (CVSS 5.5) vulnerability in tty: hvc_iucv: fix off-by-one in number of supported devices. 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.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <3d3b89e6ab93bdd0efd45828bda6b0e61cc46dff || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <484357dff256c816d9466bda35eb765685e4dc86 || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <11207e42a332eb8bbcb9fe74df9edd2a807c5607 || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <fed8b8f33a46db0ee2efdb000f4f630c86ed8ca4 || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <a76511bc654819425d3b15e77b523d7f9d81f064 || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <3104a3f40feb107f77d7116ad9bf6c210ab7babf || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <f1dc8e72de9aabe5d96767a4e97219ac26b79fe5 || >=44a01d5ba8a4d543694461cd3e178cfa6b3f221b <f2a880e802ad12d1e38039d1334fb1475d0f5241 | 3d3b89e6ab93bdd0efd45828bda6b0e61cc46dff, 484357dff256c816d9466bda35eb765685e4dc86, 11207e42a332eb8bbcb9fe74df9edd2a807c5607, fed8b8f33a46db0ee2efdb000f4f630c86ed8ca4, a76511bc654819425d3b15e77b523d7f9d81f064, 3104a3f40feb107f77d7116ad9bf6c210ab7babf, f1dc8e72de9aabe5d96767a4e97219ac26b79fe5, f2a880e802ad12d1e38039d1334fb1475d0f5241 |
| Linux/Linuxgeneric | 2.6.29 | Not reported |
Published upstream
Jun 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 26, 2026
In the Linux kernel, the following vulnerability has been resolved: tty: hvc_iucv: fix off-by-one in number of supported devices MAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8. This is the number of entries in: static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; Sometimes hvc_iucv_table[] is limited by: (a) if (num > hvc_iucv_devices) // for error detection or (b) for (i = 0; i < hvc_iucv_devices; i++) // in 2 places (so these 2 don't agree; second one appears to be correct to me.) hvc_iucv_devices can be 0..8. This is a counter. (c) if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) If hvc_iucv_devices == 8, (a) allows the code to access hvc_iucv_table[8]. Oops.
Quoted source text, attributed separately from HOL analysis.