CVE-2023-40359: xterm before 380 supports ReGIS reporting for character-set names even if they have unexpected characters (i.e

Q: How do I fix CVE-2023-40359?

xterm: upgrade to 380. Exact commands for each OS are on this page.

Q: Is CVE-2023-40359 being exploited?

CVE-2023-40359 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-40359 affect?

CVE-2023-40359 affects xterm. Severity is critical (CVSS 9.8). 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 config

Q: How urgent is CVE-2023-40359?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2023-40359 is a critical-severity flaw (CVSS 9.8) affecting xterm. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 42%)
CISA exploited list	No
Published	2023-08-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: invisible-island

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-08-14 17:15 UTCPublished CVE record published
2026-06-17 06:17 UTCUpdated Record last modified

invisible-island xterm UPGRADE

Affected: < 380

Fixed in: 380

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy xterm || rpm -q xterm || xterm --version

2. UPGRADE to 380 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade xterm

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade xterm

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-40359?

xterm: upgrade to 380. Exact commands for each OS are on this page.

Is CVE-2023-40359 being exploited?

CVE-2023-40359 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-40359 affect?

CVE-2023-40359 affects xterm. Severity is critical (CVSS 9.8). 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 config

How urgent is CVE-2023-40359?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2022-45063 CRITICAL 9.8 UPGRADE MITIGATE xterm before 375 allows code execution via font ops, e.g., because an OSC 50 response may have Ctrl-g and ther
CVE-2022-24130 MEDIUM 5.5 UPGRADE MITIGATE xterm through Patch 370, when Sixel support is enabled, allows attackers to trigger a buffer overflow in set_s
CVE-2021-27135 CRITICAL 9.8 UPGRADE MITIGATE xterm before Patch #366 allows remote attackers to execute arbitrary code or cause a denial of service (segmen
CVE-2008-2383 HIGH 9.3 DOWNGRADE CRLF injection vulnerability in xterm allows user-assisted attackers to execute arbitrary commands via LF (aka
CVE-2007-2797 LOW 2.1 DOWNGRADE xterm, including 192-7.el4 in Red Hat Enterprise Linux and 208-3.1 in Debian GNU/Linux, sets the wrong group o

References

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