How severe is CVE-2026-31742?

CVE-2026-31742 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-31742 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-31742?

CVE-2026-31742 primarily affects Linux Linux Kernel. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-31742?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-31742 have an EU (EUVD) identifier?

Yes. CVE-2026-31742 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26555.

When was CVE-2026-31742 published?

CVE-2026-31742 was published on 2026-05-01 and last updated on 2026-06-17.

CVE-2026-31742

CVE-2026-31742 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26555
Weakness: CWE-125
Affected product: Linux Linux Kernel
Published: 2026-05-01
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-31742?: 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.
How severe is CVE-2026-31742?: CVE-2026-31742 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-31742 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-31742?: CVE-2026-31742 primarily affects Linux Linux Kernel. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-31742?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-31742 have an EU (EUVD) identifier?: Yes. CVE-2026-31742 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26555.
When was CVE-2026-31742 published?: CVE-2026-31742 was published on 2026-05-01 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

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