# CVE-2026-31742: linux: In the Linux kernel, the following vulnerability has been resolved: vt: discard stale unicode buffer on alt screen e... CVE-2026-31742 is fixed in 19 products on 1 platform, first by DEBIAN-CVE-2026-31742, released May 15, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-31742 - Priority: High - CVSS: 7.8 (high) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 1, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: vt: discard stale unicode buffer on alt screen exit after resize When enter_alt_screen() saves vc_uni_lines into vc_saved_uni_lines and sets vc_uni_lines to NULL, a subsequent console resize via vc_do_resize() skips reallocating the unicode buffer because vc_uni_lines is NULL. However, vc_saved_uni_lines still points to the old buffer allocated for the original dimensions. When leave_alt_screen() later restores vc_saved_uni_lines, the buffer dimensions no longer match vc_rows/vc_cols. Any operation that iterates over the unicode buffer using the current dimensions (e.g. csi_J clearing the screen) will access memory out of bounds, causing a kernel oops: BUG: unable to handle page fault for address: 0x0000002000000020 RIP: 0010:csi_J+0x133/0x2d0 The faulting address 0x0000002000000020 is two adjacent u32 space characters (0x20) interpreted as a pointer, read from the row data area past the end of the 25-entry pointer array in a buffer allocated for 80x25 but accessed with 240x67 dimensions. Fix this by checking whether the console dimensions changed while in the alternate screen. If they did, free the stale saved buffer instead of restoring it. The unicode screen will be lazily rebuilt via vc_uniscr_check() when next needed. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel-livepatch-6.18.25-52.107 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | linux Debian 14 | 6.19.12-1 | [DEBIAN-CVE-2026-31742](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31742.md) | May 15, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.25-52.107.amzn2023 | [ALAS2023-2026-1746](https://patchblox.com/security/data/fix/linux/alas2023-2026-1746.md) | May 25, 2026 | --- Data as of 2026-11-09T07:25:28Z UTC. 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