How severe is CVE-2023-40359?

CVE-2023-40359 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-40359 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-40359?

CVE-2023-40359 affects Invisible-island Xterm. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-40359?

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

When was CVE-2023-40359 published?

CVE-2023-40359 was published on 2023-08-14 and last updated on 2026-06-17.

CVE-2023-40359

CVE-2023-40359 is a critical-severity vulnerability in Invisible-island Xterm with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Invisible-island Xterm
Published: 2023-08-14
Last modified: 2026-06-17

Description

xterm before 380 supports ReGIS reporting for character-set names even if they have unexpected characters (i.e., neither alphanumeric nor underscore), aka a pointer/overflow issue. This can only occur for xterm installations that are configured at compile time to use a certain experimental feature.

Frequently asked questions

What is CVE-2023-40359?: xterm before 380 supports ReGIS reporting for character-set names even if they have unexpected characters (i.e., neither alphanumeric nor underscore), aka a pointer/overflow issue. This can only occur for xterm installations that are configured at compile time to use a certain experimental feature.
How severe is CVE-2023-40359?: CVE-2023-40359 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-40359 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-40359?: CVE-2023-40359 affects Invisible-island Xterm. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-40359?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-40359 published?: CVE-2023-40359 was published on 2023-08-14 and last updated on 2026-06-17.

References

https://invisible-island.net/xterm/xterm.log.html#xterm_380

Affected products (1)

cpe:2.3:a:invisible-island:xterm:*:*:*:*:*:*:*:*

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