CVE-2022-23990

CRITICALNVD 7.59.8
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-02-10. NVD baseline CVSS 7.5; sources differ by 2.3.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week
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: 4.7%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Expat (aka libexpat) before 2.4.4 has an integer overflow in the doProlog function.

CVSS v3
7.5
EG Score
9.8CRITICALmedium confidence
EG Risk
61
EG Risk 61/100

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.
Exploitation4.7% × 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 partial (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
4.7%
EPSS %ILE
91st
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
4.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-22). 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: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: 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 partial (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)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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

January 26, 2022

Last Modified

October 14, 2026

Advisory Details (7)

Auto-updated Oct 13, 2026
Patch available. Sources: github_pr.
GitHub pull request

[CVE-2022-23990] lib: Prevent integer overflow in function doProlog

Fix merged in libexpat/libexpat PR #551 on 2022-01-26 — awaiting tagged release

https://github.com/libexpat/libexpat/pull/551
Web page

[R1] Nessus Versions 8.15.3 and 10.1.1 Fix Multiple Third-Party Vulnerabilities - Security Advisory | Tenable®

https://www.tenable.com/security/tns-2022-05
Web page

[SECURITY] [DSA 5073-1] expat security update

https://www.debian.org/security/2022/dsa-5073
Web page

Expat: Multiple Vulnerabilities (GLSA 202209-24) — Gentoo security

https://security.gentoo.org/glsa/202209-24
Web page

[SECURITY] Fedora 34 Update: mingw-expat-2.4.4-1.fc34 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R7FF2UH7MPXKTADYSJUAHI2Y5UHBSHUH/
Web page

[SECURITY] Fedora 35 Update: mingw-expat-2.4.4-1.fc35 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/34NXVL2RZC2YZRV74ZQ3RNFB7WCEUP7D/

Patch Availability(9)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulib64expat1 (2.1.0-4ubuntu1.4+esm4) @ trusty2026-10-23ubuntu
redhatexpat-0:2.2.10-1.el8_62025-12-09redhat
redhatexpat-0:2.2.10-1.el8_22025-12-09redhat
redhatexpat-0:2.2.10-1.el8_42025-12-04redhat
redhatexpat-0:2.2.10-1.el8_82025-12-02redhat
redhatexpat-0:2.5.0-1.el8_102025-11-19redhat
redhatmingw-expat-0:2.4.8-1.el82022-11-08redhat
redhatexpat2022-10-26redhat
redhatexpat-0:2.2.10-12.el9_02022-05-17redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(21 across 19 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
expat2.2.10-2
  • every version up to 2.2.10-2+deb11u1: fixed in 2.2.10-2+deb11u1
—
libxmltok1.2-4, 1.2-4.1, 1.2-4.1~exp1, 1.2-4.2
  • every version on: no fix on record
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-3: fixed in 2.4.3-3
—
libxmltok1.2-4, 1.2-4.1, 1.2-4.1~exp1, 1.2-4.2
  • every version on: no fix on record
—
Alpine:v3.12(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.2.10-r1: fixed in 2.2.10-r1
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.2.10-r3: fixed in 2.2.10-r3
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.4-r0: fixed in 2.4.4-r0
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
expat2.2.6-2, 2.2.6-2+deb10u1
  • every version up to 2.2.6-2+deb10u2: fixed in 2.2.6-2+deb10u2
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-3: fixed in 2.4.3-3
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-3: fixed in 2.4.3-3
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
expat2.2.0-2, 2.2.0-2+deb9u1, 2.2.0-2+deb9u2, 2.2.0-2+deb9u3
  • every version up to 2.2.0-2+deb9u4: fixed in 2.2.0-2+deb9u4
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 31× in last 7d / 66× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 98 of 219 refreshes 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 121 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-23 16:28 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  2. 2026-10-23 11:10 UTCEG score recompute
  3. 2026-10-23 11:10 UTCVendor advisory
  4. 2026-10-23 11:10 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-22 16:30 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  6. 2026-10-22 13:14 UTCEG score recompute
  7. 2026-10-22 13:14 UTCVendor advisory
  8. 2026-10-22 13:13 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-21 16:28 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  10. 2026-10-21 15:13 UTCVendor advisory
  11. 2026-10-21 15:13 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-20 17:17 UTCEG score recompute
  13. 2026-10-20 17:17 UTCVendor advisory
  14. 2026-10-20 17:17 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-20 16:29 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  16. 2026-10-19 19:19 UTCEG score recompute
  17. 2026-10-19 19:19 UTCVendor advisory
  18. 2026-10-19 19:19 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-19 16:28 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  20. 2026-10-18 21:23 UTCEG score recompute
  21. 2026-10-18 21:23 UTCVendor advisory
  22. 2026-10-18 21:23 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-18 16:28 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  24. 2026-10-18 08:42 UTCEG score recompute
  25. 2026-10-17 22:32 UTCEG score recompute
Show 73 more
  1. 2026-10-17 22:32 UTCVendor advisory
  2. 2026-10-17 22:32 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-17 16:29 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  4. 2026-10-17 00:35 UTCEG score recompute
  5. 2026-10-17 00:35 UTCVendor advisory
  6. 2026-10-17 00:34 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-16 16:34 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  8. 2026-10-16 00:18 UTCEG score recompute
  9. 2026-10-16 00:18 UTCVendor advisory
  10. 2026-10-16 00:17 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-15 16:28 UTCEPSS rescoreEPSS 4.7% · 91st percentile
  12. 2026-10-14 16:33 UTCEG score recompute
  13. 2026-10-14 16:33 UTCVendor advisory
  14. 2026-10-14 16:32 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-14 16:29 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  16. 2026-10-14 16:11 UTCVendor advisory
  17. 2026-10-14 16:11 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-13 18:21 UTCEG score recompute
  19. 2026-10-13 18:21 UTCVendor advisory
  20. 2026-10-13 18:21 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-13 16:29 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  22. 2026-10-12 18:59 UTCVendor advisory
  23. 2026-10-12 18:59 UTCGHSA enrichmentGHSA-r3g2-gw56-v728 · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-12 18:59 UTCEG score recompute
  25. 2026-10-12 16:30 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  26. 2026-10-11 23:25 UTCEG score recompute
  27. 2026-10-11 13:44 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  28. 2026-10-10 19:56 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  29. 2026-10-09 20:04 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  30. 2026-10-08 16:40 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  31. 2026-10-07 23:45 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  32. 2026-10-06 15:14 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  33. 2026-10-05 17:40 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  34. 2026-10-03 14:22 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  35. 2026-09-30 15:50 UTCEG score recompute
  36. 2026-09-30 15:00 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  37. 2026-09-29 15:15 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  38. 2026-09-27 13:41 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  39. 2026-09-26 00:22 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  40. 2026-09-25 07:05 UTCOSV refresh
  41. 2026-09-24 14:00 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  42. 2026-09-23 13:45 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  43. 2026-09-17 19:23 UTCEPSS rescoreEPSS 4.0% · 90th percentile
  44. 2026-09-16 14:05 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  45. 2026-09-15 03:06 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  46. 2026-09-13 16:43 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  47. 2026-09-12 14:57 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  48. 2026-09-11 14:49 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  49. 2026-09-11 09:33 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  50. 2026-09-08 21:57 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  51. 2026-09-07 15:58 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  52. 2026-09-06 13:45 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  53. 2026-09-05 22:30 UTCOSV refresh
  54. 2026-09-05 15:25 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  55. 2026-09-04 13:57 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  56. 2026-09-04 05:04 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  57. 2026-09-02 14:09 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  58. 2026-09-01 13:51 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  59. 2026-08-30 19:14 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  60. 2026-08-30 01:19 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  61. 2026-08-28 21:38 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  62. 2026-08-27 14:22 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  63. 2026-08-26 14:43 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  64. 2026-08-25 13:46 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  65. 2026-08-24 14:13 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  66. 2026-08-21 23:46 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  67. 2026-08-20 22:52 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  68. 2026-08-19 17:01 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  69. 2026-08-19 09:32 UTCOSV refresh
  70. 2026-08-18 13:45 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  71. 2026-08-17 13:44 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  72. 2026-08-16 14:53 UTCEPSS rescoreEPSS 4.0% · 89th percentile
  73. 2026-08-16 02:11 UTCEPSS rescoreEPSS 4.0% · 89th percentile

Frequently asked(5)

What is CVE-2022-23990?
CVE-2022-23990 is a critical-severity vulnerability; its CVE record was published on January 26, 2022. Expat (aka libexpat) before 2.4.4 has an integer overflow in the doProlog function.
When was the CVE record for CVE-2022-23990 published?
The CVE record for CVE-2022-23990 was published on January 26, 2022. 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 October 14, 2026; the record at its source may have been updated since.
Is CVE-2022-23990 actively exploited?
CVE-2022-23990 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4.7% probability of exploitation in the next 30 days (91st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2022-23990?
CVE-2022-23990 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.8 (CRITICAL).
How do I remediate CVE-2022-23990?
A fix for CVE-2022-23990 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2022-23990 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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