CVE-2021-41079

HIGHNVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 7.2% (94th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this week
7.5EG
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: 7.2%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Apache Tomcat 8.5.0 to 8.5.63, 9.0.0-M1 to 9.0.43 and 10.0.0-M1 to 10.0.2 did not properly validate incoming TLS packets. When Tomcat was configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS, a specially crafted packet could be used to trigger an infinite loop resulting in a denial of service.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
52
EG Risk 52/100

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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation7.2% × 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
7.2%
EPSS %ILE
94th
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 (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 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
7.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-20). 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 16, 2021

Last Modified

October 8, 2026

Patch Availability(5)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntutomcat9-examples (9.0.31-1ubuntu0.2) @ focal2026-10-21ubuntu
ubuntutomcat8-user (8.0.32-1ubuntu1.13+esm1) @ xenial2026-10-21ubuntu
redhattomcat2022-07-07redhat
redhatpatch2021-10-06redhat
redhatjws5-tomcat-0:9.0.43-13.redhat_00013.1.el8jws2021-10-06redhat

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

(7 across 7 ecosystems)
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat99.0.16-4 ... 9.0.31-1~deb10u5 (11 versions)
  • every version up to 9.0.31-1~deb10u6: fixed in 9.0.31-1~deb10u6
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat99.0.43-1, 9.0.43-2~deb11u1
  • every version up to 9.0.43-2~deb11u2: fixed in 9.0.43-2~deb11u2
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.53-1: fixed in 9.0.53-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.53-1: fixed in 9.0.53-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.53-1: fixed in 9.0.53-1
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat88.5.14-1 ... 8.5.54-0+deb9u7 (44 versions)
  • every version up to 8.5.54-0+deb9u8: fixed in 8.5.54-0+deb9u8
—
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.apache.tomcat:tomcat8.5.0 ... 8.5.9 (51 versions)
  • 10.0.0 up to 10.0.4: fixed in 10.0.4
  • 9.0.0 up to 9.0.44: fixed in 9.0.44
  • 8.5.0 up to 8.5.64: fixed in 8.5.64
—

Weakness Classification(2)

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 9× in last 7d / 39× 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 96 of 201 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. 4 repeat rows among the latest 100 are merged into the row they repeat. The 105 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 7.2% · 94th percentile
  2. 2026-10-22 16:29 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  3. 2026-10-21 16:28 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  4. 2026-10-21 09:00 UTCEG score recompute
  5. 2026-10-21 09:00 UTCVendor advisory
  6. 2026-10-20 16:28 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  7. 2026-10-19 16:28 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  8. 2026-10-18 08:54 UTCEG score recompute
  9. 2026-10-17 16:29 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  10. 2026-10-16 16:34 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  11. 2026-10-15 16:28 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  12. 2026-10-14 16:29 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  13. 2026-10-13 16:28 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  14. 2026-10-12 19:10 UTCEG score recompute
  15. 2026-10-12 16:30 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  16. 2026-10-11 23:35 UTCEG score recompute
  17. 2026-10-11 13:44 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  18. 2026-10-10 19:56 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  19. 2026-10-09 20:04 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  20. 2026-10-08 22:28 UTCVendor advisory
  21. 2026-10-08 21:33 UTCEG score recompute
  22. 2026-10-08 21:33 UTCVendor advisory
  23. 2026-10-08 16:40 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  24. 2026-10-07 23:45 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  25. 2026-10-06 15:14 UTCEPSS rescoreEPSS 7.2% · 94th percentile
Show 71 more
  1. 2026-10-05 17:40 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  2. 2026-10-04 23:19 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  3. 2026-10-03 14:22 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  4. 2026-10-02 16:23 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  5. 2026-10-01 19:46 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  6. 2026-09-30 15:41 UTCEG score recompute
  7. 2026-09-30 15:00 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  8. 2026-09-29 15:15 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  9. 2026-09-28 13:47 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  10. 2026-09-27 13:41 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  11. 2026-09-26 15:54 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  12. 2026-09-26 00:21 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  13. 2026-09-25 17:15 UTCOSV refresh
  14. 2026-09-24 14:00 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  15. 2026-09-23 13:44 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  16. 2026-09-22 14:44 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  17. 2026-09-21 20:28 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  18. 2026-09-19 15:38 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  19. 2026-09-18 19:23 UTCEPSS rescoreEPSS 7.2% · 94th percentile
  20. 2026-09-17 19:23 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  21. 2026-09-16 14:05 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  22. 2026-09-15 03:06 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  23. 2026-09-12 14:57 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  24. 2026-09-11 14:49 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  25. 2026-09-11 09:33 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  26. 2026-09-08 21:56 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  27. 2026-09-07 15:58 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  28. 2026-09-06 13:45 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  29. 2026-09-06 07:52 UTCOSV refresh
  30. 2026-09-05 15:25 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  31. 2026-09-04 13:57 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  32. 2026-09-04 05:03 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  33. 2026-09-02 14:09 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  34. 2026-09-01 13:50 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  35. 2026-09-01 03:33 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  36. 2026-08-30 19:14 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  37. 2026-08-30 01:19 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  38. 2026-08-28 21:37 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  39. 2026-08-27 14:22 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  40. 2026-08-26 14:43 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  41. 2026-08-25 13:46 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  42. 2026-08-24 14:13 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  43. 2026-08-23 00:16 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  44. 2026-08-21 23:46 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  45. 2026-08-20 22:52 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  46. 2026-08-19 18:12 UTCOSV refresh
  47. 2026-08-19 17:01 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  48. 2026-08-18 13:45 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  49. 2026-08-17 13:44 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  50. 2026-08-16 14:53 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  51. 2026-08-16 02:11 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  52. 2026-08-15 01:27 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  53. 2026-08-13 21:57 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  54. 2026-08-12 13:48 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  55. 2026-08-11 13:38 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  56. 2026-08-09 13:44 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  57. 2026-08-08 16:33 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  58. 2026-08-07 16:24 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  59. 2026-08-06 13:44 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  60. 2026-08-05 19:14 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  61. 2026-08-04 13:59 UTCOSV refresh
  62. 2026-08-04 10:34 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  63. 2026-08-03 10:33 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  64. 2026-08-02 02:24 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  65. 2026-08-01 04:13 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  66. 2026-07-30 16:25 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  67. 2026-07-30 01:28 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  68. 2026-07-28 15:33 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  69. 2026-07-25 14:15 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  70. 2026-07-24 14:15 UTCEPSS rescoreEPSS 7.2% · 93rd percentile
  71. 2026-07-23 14:16 UTCEPSS rescoreEPSS 7.2% · 93rd percentile

Frequently asked(5)

What is CVE-2021-41079?
CVE-2021-41079 is a high-severity vulnerability; its CVE record was published on September 16, 2021. Apache Tomcat 8.5.0 to 8.5.63, 9.0.0-M1 to 9.0.43 and 10.0.0-M1 to 10.0.2 did not properly validate incoming TLS packets. When Tomcat was configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS, a specially crafted packet could be used to trigger an infinite loop resulting in a denial of service.
When was the CVE record for CVE-2021-41079 published?
The CVE record for CVE-2021-41079 was published on September 16, 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 8, 2026; the record at its source may have been updated since.
Is CVE-2021-41079 actively exploited?
CVE-2021-41079 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 7.2% probability of exploitation in the next 30 days (94th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2021-41079?
CVE-2021-41079 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2021-41079?
A fix for CVE-2021-41079 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2021-41079 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-2021-41079

Explore →

Is Your Infrastructure Affected by CVE-2021-41079?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.