CVE-2021-22945

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-24. NVD baseline CVSS 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week
9.1EG
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: 6.7%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.

CVSS v3
9.1
EG Score
9.1CRITICALmedium 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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation6.7% × 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
6.7%
EPSS %ILE
93rd
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
6.7% 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

September 23, 2021

Last Modified

October 14, 2026

Advisory Details (9)

Auto-updated Aug 2, 2026
Patch available.
Web page

[SECURITY] [DSA 5197-1] curl security update

https://www.debian.org/security/2022/dsa-5197
Web page

About the security content of macOS Monterey 12.3 - Apple Support

https://support.apple.com/kb/HT213183
Web page

curl: Multiple Vulnerabilities (GLSA 202212-01) — Gentoo security

https://security.gentoo.org/glsa/202212-01
Web page

[SECURITY] Fedora 33 Update: curl-7.71.1-11.fc33 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/
Web page

[SECURITY] Fedora 35 Update: curl-7.79.1-1.fc35 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/
Web page

Full Disclosure: APPLE-SA-2022-03-14-4 macOS Monterey 12.3

http://seclists.org/fulldisclosure/2022/Mar/29

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntucurl (7.74.0-1ubuntu2.3) @ hirsute2026-10-22ubuntu

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

(18 across 18 ecosystems)
Alpine:v3.11(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.12(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.0-r0: fixed in 7.79.0-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
curl7.74.0-1.3, 7.74.0-1.3+deb11u1
  • every version up to 7.74.0-1.3+deb11u2: fixed in 7.74.0-1.3+deb11u2
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.1-1: fixed in 7.79.1-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.1-1: fixed in 7.79.1-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
curl—
  • every version up to 7.79.1-1: fixed in 7.79.1-1
—

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 27× in last 7d / 62× 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 95 of 222 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. 5 repeat rows among the latest 100 are merged into the row they repeat. The 127 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-22 21:10 UTCEG score recompute
  2. 2026-10-22 21:10 UTCVendor advisory
  3. 2026-10-22 21:10 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  4. 2026-10-22 16:29 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  5. 2026-10-21 21:53 UTCEG score recompute
  6. 2026-10-21 21:53 UTCVendor advisory
  7. 2026-10-21 21:53 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  8. 2026-10-21 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  9. 2026-10-20 21:57 UTCEG score recompute
  10. 2026-10-20 21:57 UTCVendor advisory
  11. 2026-10-20 21:57 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  12. 2026-10-20 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  13. 2026-10-19 22:39 UTCEG score recompute
  14. 2026-10-19 22:39 UTCVendor advisory
  15. 2026-10-19 22:39 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  16. 2026-10-19 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  17. 2026-10-18 21:23 UTCEG score recompute
  18. 2026-10-18 21:23 UTCVendor advisory
  19. 2026-10-18 21:23 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  20. 2026-10-18 09:09 UTCEG score recompute
  21. 2026-10-17 21:28 UTCEG score recompute
  22. 2026-10-17 21:28 UTCVendor advisory
  23. 2026-10-17 21:28 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-10-17 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  25. 2026-10-16 22:11 UTCEG score recompute
Show 70 more
  1. 2026-10-16 22:10 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  2. 2026-10-16 16:33 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  3. 2026-10-15 18:46 UTCEG score recompute
  4. 2026-10-15 18:46 UTCVendor advisory
  5. 2026-10-15 18:46 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  6. 2026-10-15 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  7. 2026-10-14 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  8. 2026-10-14 12:25 UTCVendor advisory
  9. 2026-10-14 12:25 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-10-14 11:30 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  11. 2026-10-13 23:17 UTCEG score recompute
  12. 2026-10-13 23:17 UTCVendor advisory
  13. 2026-10-13 23:17 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  14. 2026-10-13 16:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  15. 2026-10-12 19:24 UTCVendor advisory
  16. 2026-10-12 19:24 UTCGHSA enrichmentGHSA-22mx-9r92-42g8 · GitHub severity CRITICAL · GitHub CVSS 9.1
  17. 2026-10-12 19:23 UTCEG score recompute
  18. 2026-10-12 16:29 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  19. 2026-10-11 23:49 UTCEG score recompute
  20. 2026-10-11 13:43 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  21. 2026-10-10 19:56 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  22. 2026-10-09 20:04 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  23. 2026-10-08 16:39 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  24. 2026-10-07 23:44 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  25. 2026-10-06 15:13 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  26. 2026-10-05 17:40 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  27. 2026-10-03 14:22 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  28. 2026-10-02 16:22 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  29. 2026-10-01 19:46 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  30. 2026-09-30 15:30 UTCEG score recompute
  31. 2026-09-30 15:00 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  32. 2026-09-28 13:47 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  33. 2026-09-27 13:41 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  34. 2026-09-26 15:54 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  35. 2026-09-26 00:21 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  36. 2026-09-25 16:45 UTCOSV refresh
  37. 2026-09-24 14:00 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  38. 2026-09-23 13:44 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  39. 2026-09-22 14:44 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  40. 2026-09-21 20:28 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  41. 2026-09-19 15:37 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  42. 2026-09-18 19:23 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  43. 2026-09-17 19:23 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  44. 2026-09-16 14:04 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  45. 2026-09-15 03:06 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  46. 2026-09-13 16:43 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  47. 2026-09-12 14:57 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  48. 2026-09-11 09:33 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  49. 2026-09-10 09:29 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  50. 2026-09-08 21:56 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  51. 2026-09-07 15:58 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  52. 2026-09-06 13:44 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  53. 2026-09-06 07:22 UTCOSV refresh
  54. 2026-09-05 15:25 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  55. 2026-09-04 13:57 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  56. 2026-09-04 05:03 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  57. 2026-09-02 14:08 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  58. 2026-09-01 13:50 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  59. 2026-09-01 03:32 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  60. 2026-08-30 19:14 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  61. 2026-08-30 01:19 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  62. 2026-08-28 21:37 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  63. 2026-08-27 14:22 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  64. 2026-08-26 14:42 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  65. 2026-08-25 13:45 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  66. 2026-08-23 00:16 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  67. 2026-08-21 23:46 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  68. 2026-08-20 22:52 UTCEPSS rescoreEPSS 6.7% · 93rd percentile
  69. 2026-08-19 17:58 UTCOSV refresh
  70. 2026-08-19 17:01 UTCEPSS rescoreEPSS 6.7% · 93rd percentile

Frequently asked(5)

What is CVE-2021-22945?
CVE-2021-22945 is a critical-severity vulnerability; its CVE record was published on September 23, 2021. When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it again.
When was the CVE record for CVE-2021-22945 published?
The CVE record for CVE-2021-22945 was published on September 23, 2021. 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-2021-22945 actively exploited?
CVE-2021-22945 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.7% probability of exploitation in the next 30 days (93rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-22945?
CVE-2021-22945 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2021-22945?
A fix for CVE-2021-22945 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-22945 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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