CVE-2022-22823

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 2022-02-10. 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-2022-27961 (ENISA EUVD) · GHSA-g654-6pp3-8m8w (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: 3.9%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

build_model in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.

CVSS v3
9.8
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.
Exploitation3.9% × 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
3.9%
EPSS %ILE
90th
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
3.9% 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

January 10, 2022

Last Modified

October 14, 2026

Advisory Details (6)

Auto-updated Nov 8, 2026
Patch available. Sources: github_pr.
Web page

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

https://security.gentoo.org/glsa/202209-24
GitHub pull request

[CVE-2022-22822 to CVE-2022-22827] lib: Prevent more integer overflows

Fix merged in libexpat/libexpat PR #539 on 2022-01-13 — awaiting tagged release

https://github.com/libexpat/libexpat/pull/539
Web page

oss-security - Expat 2.4.3 released, includes 8 security fixes

http://www.openwall.com/lists/oss-security/2022/01/17/3
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

Patch Availability(14)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibxmltok1t64 (1.2-4.1ubuntu3.1) @ oracular2026-11-12ubuntu
ubuntulib64expat1 (2.1.0-4ubuntu1.4+esm4) @ trusty2026-11-12ubuntu
ubuntulibxmltok1-dev (1.2-3ubuntu0.16.04.1~esm2) @ xenial2026-11-12ubuntu
redhatexpat-0:2.2.10-1.el8_22025-12-09redhat
redhatexpat-0:2.2.10-1.el8_42025-12-04redhat
redhatxmlrpc-c-0:1.51.0-8.el82022-11-08redhat
redhatexpat2022-10-26redhat
redhatexpat-0:2.2.10-12.el9_02022-05-17redhat
redhatexpat-0:2.1.0-14.el7_92022-03-28redhat
redhatexpat-0:2.2.5-4.el8_5.32022-03-16redhat
redhatthunderbird-0:91.7.0-2.el7_92022-03-14redhat
redhatthunderbird-0:91.7.0-2.el8_52022-03-14redhat
redhatfirefox-0:91.7.0-3.el7_92022-03-10redhat
redhatfirefox-0:91.7.0-3.el8_52022-03-10redhat

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 2.4.3-1: fixed in 2.4.3-1
—
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-r0: fixed in 2.2.10-r0
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.2.10-r2: fixed in 2.2.10-r2
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-r0: fixed in 2.4.3-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 2.4.3-1: fixed in 2.4.3-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
expat—
  • every version up to 2.4.3-1: fixed in 2.4.3-1
—
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

(3)

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 21× in last 7d / 86× 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 304 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 204 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:41 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  2. 2026-11-13 07:59 UTCEchelonGraph re-scored
  3. 2026-11-13 07:59 UTCVendor advisory
  4. 2026-11-13 07:59 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-11-12 16:29 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  6. 2026-11-12 06:52 UTCEchelonGraph re-scored
  7. 2026-11-12 06:52 UTCVendor advisory
  8. 2026-11-12 06:52 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-11-11 16:32 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  10. 2026-11-11 05:44 UTCEchelonGraph re-scored
  11. 2026-11-11 05:44 UTCVendor advisory
  12. 2026-11-11 05:44 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-10 16:35 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  14. 2026-11-10 04:37 UTCEchelonGraph re-scored
  15. 2026-11-10 04:37 UTCVendor advisory
  16. 2026-11-10 04:37 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-09 16:29 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  18. 2026-11-09 03:30 UTCEchelonGraph re-scored
  19. 2026-11-09 03:30 UTCVendor advisory
  20. 2026-11-09 03:30 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-08 16:33 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  22. 2026-11-08 02:23 UTCEchelonGraph re-scored
  23. 2026-11-08 02:23 UTCVendor advisory
  24. 2026-11-08 02:23 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-07 16:34 UTCEPSS rescoreEPSS 3.9% · 90th percentile
Show 75 more
  1. 2026-11-07 01:16 UTCEchelonGraph re-scored
  2. 2026-11-07 01:16 UTCVendor advisory
  3. 2026-11-07 01:16 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-06 16:30 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  5. 2026-11-06 00:07 UTCEchelonGraph re-scored
  6. 2026-11-06 00:07 UTCVendor advisory
  7. 2026-11-06 00:07 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-11-05 16:31 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  9. 2026-11-04 22:59 UTCEchelonGraph re-scored
  10. 2026-11-04 22:59 UTCVendor advisory
  11. 2026-11-04 22:59 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-04 16:30 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  13. 2026-11-03 23:55 UTCOSV refresh
  14. 2026-11-03 21:51 UTCEchelonGraph re-scored
  15. 2026-11-03 21:51 UTCVendor advisory
  16. 2026-11-03 21:51 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-03 16:39 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  18. 2026-11-02 20:44 UTCEchelonGraph re-scored
  19. 2026-11-02 20:44 UTCVendor advisory
  20. 2026-11-02 20:44 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-01 19:36 UTCEchelonGraph re-scored
  22. 2026-11-01 19:36 UTCVendor advisory
  23. 2026-11-01 19:36 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-11-01 16:30 UTCEPSS rescoreEPSS 3.9% · 90th percentile
  25. 2026-10-31 18:30 UTCEchelonGraph re-scored
  26. 2026-10-31 18:30 UTCVendor advisory
  27. 2026-10-31 18:30 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-31 16:29 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  29. 2026-10-30 17:13 UTCEchelonGraph re-scored
  30. 2026-10-30 17:13 UTCVendor advisory
  31. 2026-10-30 17:13 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  32. 2026-10-30 16:30 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  33. 2026-10-29 16:29 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  34. 2026-10-29 16:06 UTCEchelonGraph re-scored
  35. 2026-10-29 16:06 UTCVendor advisory
  36. 2026-10-29 16:06 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-28 16:28 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  38. 2026-10-28 14:59 UTCEchelonGraph re-scored
  39. 2026-10-28 14:59 UTCVendor advisory
  40. 2026-10-28 14:59 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-27 16:28 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  42. 2026-10-27 13:38 UTCEchelonGraph re-scored
  43. 2026-10-27 13:38 UTCVendor advisory
  44. 2026-10-27 13:38 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-26 16:28 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  46. 2026-10-26 11:59 UTCVendor advisory
  47. 2026-10-26 11:59 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  48. 2026-10-25 18:14 UTCEchelonGraph re-scored
  49. 2026-10-25 16:29 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  50. 2026-10-25 10:38 UTCEchelonGraph re-scored
  51. 2026-10-25 10:38 UTCVendor advisory
  52. 2026-10-25 10:38 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-24 16:29 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  54. 2026-10-24 09:31 UTCEchelonGraph re-scored
  55. 2026-10-24 09:31 UTCVendor advisory
  56. 2026-10-24 09:31 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-23 16:28 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  58. 2026-10-23 08:24 UTCEchelonGraph re-scored
  59. 2026-10-23 08:24 UTCVendor advisory
  60. 2026-10-23 08:24 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-22 16:30 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  62. 2026-10-22 07:14 UTCEchelonGraph re-scored
  63. 2026-10-22 07:14 UTCVendor advisory
  64. 2026-10-22 07:14 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-21 16:28 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  66. 2026-10-21 06:08 UTCEchelonGraph re-scored
  67. 2026-10-21 06:08 UTCVendor advisory
  68. 2026-10-21 06:08 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-20 16:29 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  70. 2026-10-20 05:00 UTCEchelonGraph re-scored
  71. 2026-10-20 05:00 UTCVendor advisory
  72. 2026-10-20 04:59 UTCGHSA enrichmentGHSA-g654-6pp3-8m8w · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-10-19 16:28 UTCEPSS rescoreEPSS 3.6% · 89th percentile
  74. 2026-10-19 03:49 UTCEchelonGraph re-scored
  75. 2026-10-19 03:49 UTCVendor advisory

Frequently asked(5)

What is CVE-2022-22823?
CVE-2022-22823 is a critical-severity vulnerability; its CVE record was published on January 10, 2022. build_model in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.
When was the CVE record for CVE-2022-22823 published?
The CVE record for CVE-2022-22823 was published on January 10, 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-2022-22823 actively exploited?
CVE-2022-22823 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.9% probability of exploitation in the next 30 days (90th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2022-22823?
CVE-2022-22823 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2022-22823?
A fix for CVE-2022-22823 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2022-22823 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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