CVE-2023-40359

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2023-08-14. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2023-44930 (ENISA EUVD) · GHSA-cwvr-vg72-6p6j (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.9% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.9%
EPSS %ILE
58th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 14, 2023

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated Oct 10, 2026
Patch available.

Vendor Advisories for CVE-2023-40359(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
xterm366-1 ... 410-1 (48 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
xterm379-1 ... 412-1 (33 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
xterm—
  • every version up to 382-2: fixed in 382-2
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
xterm—
  • every version up to 382-2: fixed in 382-2
—

Data Freshness Timeline

(refreshed 16× in last 7d / 76× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 314 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 214 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 19:52 UTCEchelonGraph re-scored
  2. 2026-11-12 19:52 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-12 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  4. 2026-11-11 17:32 UTCEchelonGraph re-scored
  5. 2026-11-11 17:32 UTCVendor advisory
  6. 2026-11-11 17:32 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-11-11 16:33 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  8. 2026-11-10 16:37 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  9. 2026-11-10 15:08 UTCEchelonGraph re-scored
  10. 2026-11-10 15:08 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-11-09 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  12. 2026-11-09 12:49 UTCEchelonGraph re-scored
  13. 2026-11-09 12:49 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-11-08 16:35 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  15. 2026-11-08 10:30 UTCEchelonGraph re-scored
  16. 2026-11-08 10:30 UTCVendor advisory
  17. 2026-11-08 10:30 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-11-07 16:35 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  19. 2026-11-07 08:11 UTCEchelonGraph re-scored
  20. 2026-11-07 08:11 UTCVendor advisory
  21. 2026-11-07 08:11 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-11-06 16:31 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  23. 2026-11-06 05:50 UTCEchelonGraph re-scored
  24. 2026-11-06 05:50 UTCVendor advisory
  25. 2026-11-06 05:50 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
Show 75 more
  1. 2026-11-05 16:33 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  2. 2026-11-05 03:31 UTCEchelonGraph re-scored
  3. 2026-11-05 03:31 UTCVendor advisory
  4. 2026-11-05 03:31 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-11-04 16:31 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  6. 2026-11-04 15:25 UTCOSV refresh
  7. 2026-11-04 01:11 UTCEchelonGraph re-scored
  8. 2026-11-04 01:11 UTCVendor advisory
  9. 2026-11-04 01:11 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-11-03 16:41 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  11. 2026-11-02 22:48 UTCEchelonGraph re-scored
  12. 2026-11-02 22:48 UTCVendor advisory
  13. 2026-11-02 22:48 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-11-02 16:40 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  15. 2026-11-01 20:27 UTCEchelonGraph re-scored
  16. 2026-11-01 20:27 UTCVendor advisory
  17. 2026-11-01 20:27 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-11-01 16:31 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  19. 2026-10-31 18:08 UTCEchelonGraph re-scored
  20. 2026-10-31 18:08 UTCVendor advisory
  21. 2026-10-31 18:08 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  23. 2026-10-30 16:31 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  24. 2026-10-30 15:48 UTCEchelonGraph re-scored
  25. 2026-10-30 15:48 UTCVendor advisory
  26. 2026-10-30 15:48 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  27. 2026-10-29 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  28. 2026-10-29 13:29 UTCEchelonGraph re-scored
  29. 2026-10-29 13:29 UTCVendor advisory
  30. 2026-10-29 13:28 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-28 16:29 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  32. 2026-10-28 11:09 UTCEchelonGraph re-scored
  33. 2026-10-28 11:09 UTCVendor advisory
  34. 2026-10-28 11:09 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  35. 2026-10-27 16:29 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  36. 2026-10-27 08:08 UTCEchelonGraph re-scored
  37. 2026-10-27 08:08 UTCVendor advisory
  38. 2026-10-27 08:08 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  39. 2026-10-26 16:28 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  40. 2026-10-26 03:33 UTCVendor advisory
  41. 2026-10-26 03:33 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  42. 2026-10-25 17:37 UTCEchelonGraph re-scored
  43. 2026-10-25 16:29 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  44. 2026-10-25 01:09 UTCEchelonGraph re-scored
  45. 2026-10-25 01:09 UTCVendor advisory
  46. 2026-10-25 01:09 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  47. 2026-10-24 16:29 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  48. 2026-10-23 22:50 UTCEchelonGraph re-scored
  49. 2026-10-23 22:50 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-10-23 16:29 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  51. 2026-10-22 20:16 UTCEchelonGraph re-scored
  52. 2026-10-22 20:16 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  54. 2026-10-21 17:54 UTCEchelonGraph re-scored
  55. 2026-10-21 17:54 UTCVendor advisory
  56. 2026-10-21 17:54 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-21 16:29 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  58. 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  59. 2026-10-20 15:35 UTCEchelonGraph re-scored
  60. 2026-10-20 15:35 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-19 16:29 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  62. 2026-10-19 13:16 UTCEchelonGraph re-scored
  63. 2026-10-19 13:16 UTCVendor advisory
  64. 2026-10-19 13:16 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-18 16:29 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  66. 2026-10-18 10:57 UTCVendor advisory
  67. 2026-10-18 10:57 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-10-18 07:53 UTCEchelonGraph re-scored
  69. 2026-10-17 16:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  70. 2026-10-17 05:41 UTCEchelonGraph re-scored
  71. 2026-10-17 05:41 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-10-16 16:36 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  73. 2026-10-16 03:21 UTCEchelonGraph re-scored
  74. 2026-10-16 03:21 UTCGHSA enrichmentGHSA-cwvr-vg72-6p6j · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-10-15 16:29 UTCEPSS rescoreEPSS 0.9% · 57th percentile

Frequently asked(5)

What is CVE-2023-40359?
CVE-2023-40359 is a critical-severity vulnerability; its CVE record was published on August 14, 2023. 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.
When was the CVE record for CVE-2023-40359 published?
The CVE record for CVE-2023-40359 was published on August 14, 2023. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 21, 2024; the record at its source may have been updated since.
Is CVE-2023-40359 actively exploited?
CVE-2023-40359 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (58th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-40359?
CVE-2023-40359 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2023-40359?
A fix for CVE-2023-40359 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2023-40359 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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