In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.
CVE-2020-1935
“—” beside the score: it is equal to NVD's CVSS score.
This medium-severity CVE scores 4.8 under NVD CVSS v3. EPSS exploit probability: 9.4% (95th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2020-0311 (ENISA EUVD)Source: ENISA EUVD
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 4.8
- EG Score
- 4.8MEDIUMmedium confidence
- EG Risk
- 53EG Risk 53/100
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)Severity48% × 45%Impact severity (EG Severity): CVSS 4.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.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
- 9.4%
- EPSS %ILE
- 95th
- 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 (4.8): severity, escalated by confirmed exploitation. This CVE's 4.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 4.8 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 9.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). 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
February 24, 2020
Last Modified
October 8, 2026
Advisory Details (9)
Auto-updated Oct 9, 2026Pony Mail
https://lists.apache.org/thread.html/rd547be0c9d821b4b1000a694b8e58ef9f5e2d66db03a31dfe77c4b18%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/rc31cbabb46cdc58bbdd8519a8f64b6236b2635a3922bbeba0f0e3743%40%3Ccommits.tomee.apache.org%3EPony Mail
https://lists.apache.org/thread.html/ra5dee390ad2d60307b8362505c059cd6a726de4d146d63dfce1e05e7%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r9ce7918faf347e7aac32be930bf26c233b0b140fe37af0bb294158b6%40%3Cdev.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r80e9c8417c77d52c62809168b96912bda70ddf7748f19f8210f745b1%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78%40%3Ccommits.tomee.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919%40%3Cusers.tomcat.apache.org%3EVendor Advisories for CVE-2020-1935(10)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2021:3140Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Fuse 7.9.0 release and security update
- RHSA-2021:1030Red Hat Product SecurityLow
Red Hat Security Advisory: tomcat security update
- RHSA-2021:0882Red Hat Product SecurityLow
Red Hat Security Advisory: tomcat security update
- RHSA-2020:5020Red Hat Product SecurityLow
Red Hat Security Advisory: tomcat security update
- RHSA-2020:4847Red Hat Product SecurityMedium
Red Hat Security Advisory: pki-core:10.6 and pki-deps:10.6 security, bug fix, and enhancement update
- RHSA-2020:3303Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Web Server 3.1 Service Pack 10 security update
- RHSA-2020:3305Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Web Server 3.1 Service Pack 10 security update
- RHSA-2020:2367Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat support for Spring Boot 2.1.13 security and bug fix update
- +2 more
Patch Availability(8)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | tomcat8-user (8.0.32-1ubuntu1.13) @ xenial | 2026-10-25 | ubuntu |
| redhat | tomcat | 2021-08-11 | redhat |
| redhat | tomcat-0:7.0.76-12.el7_7 | 2021-03-30 | redhat |
| redhat | tomcat-0:7.0.76-11.el7_6 | 2021-03-16 | redhat |
| redhat | tomcat-0:7.0.76-16.el7_9 | 2020-11-10 | redhat |
| redhat | pki-deps:10.6-8030020200527165326.30b713e6 | 2020-11-04 | redhat |
| redhat | tomcat8-0:8.0.36-45.ep7.el7 | 2020-08-04 | redhat |
| redhat | jws5-tomcat-native-0:1.2.23-4.redhat_4.el8jws | 2020-04-21 | redhat |
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
(10 across 8 ecosystems)
Debian:8(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat7 | 7.0.56-3 ... 7.0.56-3+really7.0.99-1 (18 versions) |
| — |
| tomcat8 | 8.0.14-1 ... 8.0.14-1+deb8u9 (17 versions) |
| — |
Maven(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| org.apache.tomcat.embed:tomcat-embed-core | 9.0.1 ... 9.0.8 (23 versions) |
| — |
| org.apache.tomcat:tomcat | 9.0.1 ... 9.0.8 (23 versions) |
| — |
Debian:10(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | 9.0.16-4 ... 9.0.31-1~bpo10+1 (6 versions) |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:9(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat8 | 8.5.14-1 ... 8.5.50-0+deb9u1 (37 versions) |
| — |
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 10× in last 7d / 37× 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 193 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 97 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-31 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-30 16:29 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-29 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-28 16:27 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-27 16:27 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-26 16:27 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-25 18:48 UTCEG score recompute
- 2026-10-25 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-25 02:17 UTCEG score recompute
- 2026-10-25 02:17 UTCVendor advisory
- 2026-10-24 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-23 16:27 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-22 16:29 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-21 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-20 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-19 16:27 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-18 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-18 09:30 UTCEG score recompute
- 2026-10-17 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-16 16:33 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-15 16:27 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-14 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-13 16:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-12 19:43 UTCEG score recompute
- 2026-10-12 16:29 UTCEPSS rescoreEPSS 9.4% · 95th percentile
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- 2026-10-12 00:06 UTCEG score recompute
- 2026-10-11 13:43 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-10 19:56 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-09 20:04 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-08 21:25 UTCEG score recompute
- 2026-10-08 21:25 UTCVendor advisory
- 2026-10-08 16:38 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-07 23:44 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-06 15:13 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-05 17:39 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-03 14:22 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-10-02 16:22 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-30 15:14 UTCEG score recompute
- 2026-09-30 14:59 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-27 13:40 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-27 08:32 UTCOSV refresh
- 2026-09-26 15:54 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-26 00:20 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-24 14:00 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-22 14:43 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-21 20:28 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-20 20:11 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-18 19:23 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-17 19:22 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-16 14:04 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-15 03:06 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-13 16:42 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-12 14:56 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-11 14:48 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-11 09:32 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-10 09:29 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-08 21:56 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-07 17:51 UTCOSV refresh
- 2026-09-07 15:57 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-06 13:44 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-05 15:24 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-04 13:57 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-04 05:03 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-02 14:08 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-09-01 03:32 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-30 19:14 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-30 01:18 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-27 14:21 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-26 14:42 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-25 13:45 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-21 23:45 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-21 03:53 UTCOSV refresh
- 2026-08-20 22:52 UTCEPSS rescoreEPSS 9.4% · 95th percentile
- 2026-08-19 17:00 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-18 13:44 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-16 14:52 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-16 02:11 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-15 01:26 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-13 21:57 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-12 13:47 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-09 13:43 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-08 16:33 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-07 16:23 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-06 13:43 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-05 19:14 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-05 19:10 UTCOSV refresh
- 2026-08-04 15:06 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-04 10:34 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-03 10:32 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-02 02:23 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-08-01 04:12 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-07-30 16:25 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-07-30 01:27 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-07-28 15:32 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-07-25 14:14 UTCEPSS rescoreEPSS 9.4% · 94th percentile
- 2026-07-24 14:14 UTCEPSS rescoreEPSS 9.4% · 94th percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:9:tomcat8
- CVE-2020-1938EG 9.8 KEVEPSS p100CRITICAL
- CVE-2020-9484NVD 7.0EG 7.9EPSS p99HIGH
- CVE-2019-17563EG 7.5EPSS p96HIGH
- CVE-2019-12418EG 7.0HIGH
- CVE-2019-17569EG 4.8EPSS p95MEDIUM
- CVE-2019-0221NVD 6.1EG 7.6EPSS p99HIGH
- CVE-2020-11996EG 7.5EPSS p98HIGH
- CVE-2021-25122EG 7.5EPSS p97HIGH
- CVE-2021-25329EG 7.0EPSS p95HIGH
- CVE-2020-13935NVD 7.5EG 9.0EPSS p100CRITICAL
Same vendor
10 shownredhat:RHSA-2020:1520 · redhat:RHSA-2020:3303 · redhat:RHSA-2021:3140
- CVE-2020-1938EG 9.8 KEVEPSS p100CRITICAL
- CVE-2020-13935NVD 7.5EG 9.0EPSS p100CRITICAL
- CVE-2019-17563EG 7.5EPSS p96HIGH
- CVE-2020-9484NVD 7.0EG 7.9EPSS p99HIGH
- CVE-2019-12418EG 7.0HIGH
- CVE-2019-17569EG 4.8EPSS p95MEDIUM
- CVE-2020-17510EG 9.8EPSS p95CRITICAL
- CVE-2017-5645EG 9.8EPSS p100CRITICAL
- CVE-2019-14887EG 9.1CRITICAL
- CVE-2019-20445EG 9.1EPSS p97CRITICAL
Same CWE
10 shownCWE-444
- CVE-2019-17569EG 4.8EPSS p95MEDIUM
- CVE-2020-5401EG 5.3MEDIUM
- CVE-2019-19223EG 7.5EPSS p91HIGH
- CVE-2020-10111EG 7.5HIGH
- CVE-2020-10112EG 5.4MEDIUM
- CVE-2015-5741EG 9.8CRITICAL
- CVE-2020-10108EG 9.8EPSS p90CRITICAL
- CVE-2020-10109EG 9.8CRITICAL
- CVE-2019-15605EG 9.8EPSS p99CRITICAL
- CVE-2019-20445EG 9.1EPSS p97CRITICAL
Frequently asked(5)
What is CVE-2020-1935?
When was the CVE record for CVE-2020-1935 published?
Is CVE-2020-1935 actively exploited?
What is the CVSS score of CVE-2020-1935?
How do I remediate CVE-2020-1935?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-1935
Is Your Infrastructure Affected by CVE-2020-1935?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.