CVE-2021-30952

CRITICALNVD 7.89.0
EchelonGraph scoreHIGH confidence

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

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-03-05), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.8 retained for reference. The 9.0 is the floor for confirmed exploitation, not an impact rating: this CVE's impact severity (EG Severity) is CVSS 7.8 HIGH under NVD CVSS v3. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, NVD CVSS v3
Trending — 3 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low or medium mission impact
CISA-KEV: ExploitedEPSS PROB: 7.0%CVSS: 7.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.

CVSS v3
7.8
EG Score
9.0CRITICALhigh confidence
EG Risk
75
EG Risk 75/100

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)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Attend at medium and Act at high mission impact.
Exploitation active (CISA Vulnrichment) · Automatable no (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, sooner than that at medium and as soon as possible at high mission impact.
EPSS PROB
7.0%
EPSS %ILE
94th
KEV
⚠ Exploited

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

The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is the CISA KEV floor for confirmed exploitation, not an impact rating: its impact severity (EG Severity) is CVSS 7.8 HIGH.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
7.0% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-22). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Attend at medium mission impactTrack at low, Attend at medium and Act at high mission impact.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 14 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, Attend at medium and Act at high mission impact.

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

Exploitation active (CISA Vulnrichment) · Automatable no (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 & forensic triage if the affected system is publicly exposed; 14 days if it is not.

In CISA KEV yes (CISA's KEV catalog) · Automatable no (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

CISA required action“Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://support.apple.com/en-us/HT212975 · https://support.apple.com/en-us/HT212976 · https://support.apple.com/en-us/HT212978 · https://support.apple.com/en-us/HT212980 · https://support.apple.com/en-us/HT212982 · https://nvd.nist.gov/vuln/detail/CVE-2021-30952

Published

August 24, 2021

Last Modified

March 6, 2026

Advisory Details (10)

Auto-updated Oct 19, 2026
⚠️ Actively exploited (CISA KEV, CISA Vulnrichment). Patch available.
Web page

[SECURITY] [DSA 5061-1] wpewebkit security update

https://www.debian.org/security/2022/dsa-5061
Web page

[SECURITY] [DSA 5060-1] webkit2gtk security update

https://www.debian.org/security/2022/dsa-5060
Web page

About the security content of Safari 15.2 - Apple Support

https://support.apple.com/en-us/HT212982
Web page

About the security content of tvOS 15.2 - Apple Support

https://support.apple.com/en-us/HT212980
Web page

About the security content of macOS Monterey 12.1 - Apple Support

https://support.apple.com/en-us/HT212978
Web page

About the security content of iOS 15.2 and iPadOS 15.2 - Apple Support

https://support.apple.com/en-us/HT212976
Web page

About the security content of watchOS 8.3 - Apple Support

https://support.apple.com/en-us/HT212975
Web page

[SECURITY] Fedora 34 Update: webkit2gtk3-2.34.4-1.fc34 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HQKWD4BXRDD2YGR5AVU7H5J5PIQIEU6V/
Web page

[SECURITY] Fedora 35 Update: webkit2gtk3-2.34.4-2.fc35 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7EQVZ3CEMTINLBZ7PBC7WRXVEVCRHNSM/
Web page

oss-security - WebKitGTK and WPE WebKit Security Advisory WSA-2022-0001

http://www.openwall.com/lists/oss-security/2022/01/21/2

Vendor Advisories for CVE-2021-30952(1)

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

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibwebkit2gtk-4.0-dev (2.34.4-0ubuntu0.21.10.1) @ impish2026-10-21ubuntu
redhatwebkitgtk4-0:2.48.3-2.el7_92025-07-07redhat
redhatwebkit2gtk3-0:2.34.6-1.el82022-05-10redhat

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

(9 across 5 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk2.32.3-1 ... 2.34.4-1~deb10u1 (20 versions)
  • every version up to 2.34.4-1~deb11u1: fixed in 2.34.4-1~deb11u1
—
wpewebkit2.32.3-2 ... 2.34.3-1~deb11u1 (8 versions)
  • every version up to 2.34.4-1~deb11u1: fixed in 2.34.4-1~deb11u1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.34.4-1: fixed in 2.34.4-1
—
wpewebkit—
  • every version up to 2.34.4-1: fixed in 2.34.4-1
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.34.4-1: fixed in 2.34.4-1
—
wpewebkit—
  • every version up to 2.34.4-1: fixed in 2.34.4-1
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk—
  • every version up to 2.34.4-1: fixed in 2.34.4-1
—
wpewebkit—
  • every version up to 2.34.4-1: fixed in 2.34.4-1
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk2.24.2-1 ... 2.34.3-1~deb11u1 (105 versions)
  • every version up to 2.34.4-1~deb10u1: fixed in 2.34.4-1~deb10u1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(2)

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 / 200× 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 100 of 1,194 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. None are among the latest 100 rows. The 1,094 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 7.0% · 94th percentile
  2. 2026-10-23 08:14 UTCEG score recompute
  3. 2026-10-23 08:14 UTCVendor advisory
  4. 2026-10-22 16:29 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  5. 2026-10-22 10:06 UTCEG score recompute
  6. 2026-10-22 10:06 UTCVendor advisory
  7. 2026-10-21 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  8. 2026-10-21 11:55 UTCEG score recompute
  9. 2026-10-21 11:55 UTCVendor advisory
  10. 2026-10-20 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  11. 2026-10-20 13:47 UTCEG score recompute
  12. 2026-10-20 13:47 UTCVendor advisory
  13. 2026-10-19 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  14. 2026-10-19 15:37 UTCVendor advisory
  15. 2026-10-18 17:28 UTCEG score recompute
  16. 2026-10-18 17:28 UTCVendor advisory
  17. 2026-10-18 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  18. 2026-10-18 09:02 UTCEG score recompute
  19. 2026-10-17 19:20 UTCEG score recompute
  20. 2026-10-17 19:20 UTCVendor advisory
  21. 2026-10-17 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  22. 2026-10-16 21:11 UTCEG score recompute
  23. 2026-10-16 21:11 UTCVendor advisory
  24. 2026-10-16 16:33 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  25. 2026-10-15 23:01 UTCEG score recompute
Show 75 more
  1. 2026-10-15 23:01 UTCVendor advisory
  2. 2026-10-15 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  3. 2026-10-15 00:54 UTCEG score recompute
  4. 2026-10-15 00:54 UTCVendor advisory
  5. 2026-10-14 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  6. 2026-10-14 02:45 UTCEG score recompute
  7. 2026-10-14 02:45 UTCVendor advisory
  8. 2026-10-13 16:28 UTCEPSS rescoreEPSS 7.0% · 94th percentile
  9. 2026-10-13 04:36 UTCVendor advisory
  10. 2026-10-12 19:17 UTCEG score recompute
  11. 2026-10-12 16:29 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  12. 2026-10-12 06:27 UTCVendor advisory
  13. 2026-10-12 02:38 UTCVendor advisory
  14. 2026-10-11 22:53 UTCEG score recompute
  15. 2026-10-11 22:53 UTCVendor advisory
  16. 2026-10-11 19:06 UTCEG score recompute
  17. 2026-10-11 19:06 UTCVendor advisory
  18. 2026-10-11 15:20 UTCEG score recompute
  19. 2026-10-11 15:20 UTCVendor advisory
  20. 2026-10-11 13:43 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  21. 2026-10-11 11:35 UTCEG score recompute
  22. 2026-10-11 11:35 UTCVendor advisory
  23. 2026-10-11 07:51 UTCVendor advisory
  24. 2026-10-11 04:05 UTCVendor advisory
  25. 2026-10-11 00:20 UTCVendor advisory
  26. 2026-10-10 20:35 UTCEG score recompute
  27. 2026-10-10 20:35 UTCVendor advisory
  28. 2026-10-10 19:56 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  29. 2026-10-10 16:49 UTCVendor advisory
  30. 2026-10-10 13:02 UTCVendor advisory
  31. 2026-10-10 09:18 UTCVendor advisory
  32. 2026-10-10 05:33 UTCVendor advisory
  33. 2026-10-10 01:48 UTCVendor advisory
  34. 2026-10-09 22:03 UTCEG score recompute
  35. 2026-10-09 22:03 UTCVendor advisory
  36. 2026-10-09 20:04 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  37. 2026-10-09 18:17 UTCVendor advisory
  38. 2026-10-09 14:32 UTCVendor advisory
  39. 2026-10-09 10:42 UTCVendor advisory
  40. 2026-10-09 06:54 UTCVendor advisory
  41. 2026-10-09 03:10 UTCVendor advisory
  42. 2026-10-08 23:25 UTCVendor advisory
  43. 2026-10-08 19:40 UTCEG score recompute
  44. 2026-10-08 19:40 UTCVendor advisory
  45. 2026-10-08 16:39 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  46. 2026-10-08 15:55 UTCVendor advisory
  47. 2026-10-08 12:10 UTCVendor advisory
  48. 2026-10-08 08:25 UTCVendor advisory
  49. 2026-10-08 04:40 UTCVendor advisory
  50. 2026-10-08 00:56 UTCEG score recompute
  51. 2026-10-08 00:56 UTCVendor advisory
  52. 2026-10-07 23:44 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  53. 2026-10-07 21:11 UTCVendor advisory
  54. 2026-10-07 17:26 UTCVendor advisory
  55. 2026-10-07 13:40 UTCVendor advisory
  56. 2026-10-07 09:54 UTCVendor advisory
  57. 2026-10-07 06:09 UTCVendor advisory
  58. 2026-10-07 02:24 UTCVendor advisory
  59. 2026-10-06 22:39 UTCVendor advisory
  60. 2026-10-06 18:54 UTCEG score recompute
  61. 2026-10-06 18:54 UTCVendor advisory
  62. 2026-10-06 15:14 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  63. 2026-10-06 15:10 UTCVendor advisory
  64. 2026-10-06 11:24 UTCVendor advisory
  65. 2026-10-06 07:39 UTCVendor advisory
  66. 2026-10-06 03:55 UTCVendor advisory
  67. 2026-10-06 00:08 UTCVendor advisory
  68. 2026-10-05 20:23 UTCEG score recompute
  69. 2026-10-05 20:23 UTCVendor advisory
  70. 2026-10-05 17:40 UTCEPSS rescoreEPSS 7.0% · 93rd percentile
  71. 2026-10-05 16:38 UTCVendor advisory
  72. 2026-10-05 12:54 UTCVendor advisory
  73. 2026-10-05 09:09 UTCVendor advisory
  74. 2026-10-05 05:22 UTCVendor advisory
  75. 2026-10-05 01:37 UTCEG score recompute

Frequently asked(6)

What is CVE-2021-30952?
CVE-2021-30952 is a critical-severity vulnerability; its CVE record was published on August 24, 2021. An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.
When was the CVE record for CVE-2021-30952 published?
The CVE record for CVE-2021-30952 was published on August 24, 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 March 6, 2026; the record at its source may have been updated since.
Is CVE-2021-30952 actively exploited?
Yes. CISA added CVE-2021-30952 to the Known Exploited Vulnerabilities catalog on March 5, 2026, affecting Apple Multiple Products. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2021-30952?
CVE-2021-30952 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
Which products are affected by CVE-2021-30952?
CVE-2021-30952 affects Apple Multiple Products. The affected packages EchelonGraph has on record, with version ranges, are listed in the Affected Packages section of this page.
How do I remediate CVE-2021-30952?
A fix for CVE-2021-30952 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-30952 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-30952

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