An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit signal are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.
CVE-2019-3857
“—” beside the score: it is equal to NVD's CVSS score.
Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-13. NVD baseline CVSS 8.8; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.8
- EG Score
- 8.8HIGHmedium confidence
- EG Risk
- 42EG Risk 42/100
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)Severity88% × 45%Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation6.1% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (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. - EPSS PROB
- 6.1%
- 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 (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 6.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-21). 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade 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; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (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
Published
March 25, 2019
Last Modified
October 14, 2026
Advisory Details (8)
Auto-updated Aug 24, 2026[SECURITY] [DLA 1730-1] libssh2 security update
https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html1687305 – (CVE-2019-3857) CVE-2019-3857 libssh2: Integer overflow in SSH packet processing channel resulting in out of bounds write
Affected: Red Hat Enterprise Linux 7
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3857Affected: Red Hat Enterprise Linux 7.3 Advanced Update Support, Red Hat Enterprise Linux 7.3 Telco Extended Update Support, and Red Hat
https://access.redhat.com/errata/RHSA-2019:2399Affected: Red Hat Enterprise Linux 7.4 Extended Update Support.
https://access.redhat.com/errata/RHSA-2019:1943Affected: Red Hat Enterprise Linux 7.5 Extended Update Support.
https://access.redhat.com/errata/RHSA-2019:1791Affected: Red Hat Enterprise Linux 6.
https://access.redhat.com/errata/RHSA-2019:1652Affected: Red Hat Enterprise Linux 8.
https://access.redhat.com/errata/RHSA-2019:1175Affected: Red Hat Enterprise Linux 7.
https://access.redhat.com/errata/RHSA-2019:0679Vendor Advisories for CVE-2019-3857(7)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- GHSA-mq4f-qjqv-2ff5GitHub Security AdvisoriesHigh
An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2...
- RHSA-2019:2399Red Hat Product SecurityHigh
Red Hat Security Advisory: libssh2 security update
- RHSA-2019:1943Red Hat Product SecurityHigh
Red Hat Security Advisory: libssh2 security update
- RHSA-2019:1791Red Hat Product SecurityHigh
Red Hat Security Advisory: libssh2 security update
- RHSA-2019:1652Red Hat Product SecurityHigh
Red Hat Security Advisory: libssh2 security update
- RHSA-2019:1175Red Hat Product SecurityHigh
Red Hat Security Advisory: virt:rhel security update
- RHSA-2019:0679Red Hat Product SecurityHigh
Red Hat Security Advisory: libssh2 security update
Patch Availability(7)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | libssh2-1 (1.5.0-2ubuntu0.1+esm1) @ xenial | 2026-10-21 | ubuntu |
| redhat | libssh2-0:1.4.3-11.el7_3.1 | 2019-08-07 | redhat |
| redhat | libssh2-0:1.4.3-11.el7_4.1 | 2019-07-30 | redhat |
| redhat | libssh2-0:1.4.3-11.el7_5.1 | 2019-07-16 | redhat |
| redhat | libssh2-0:1.4.2-3.el6_10.1 | 2019-07-02 | redhat |
| redhat | virt:rhel-8000020190510171727.55190bc5 | 2019-05-14 | redhat |
| redhat | libssh2-0:1.4.3-12.el7_6.2 | 2019-03-28 | 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
(22 across 22 ecosystems)
Alpine:v3.10(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.15(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.16(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.17(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.18(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.19(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.20(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.21(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.22(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.23(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Alpine:v3.9(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | — |
| — |
Debian:8(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | 1.4.3-4.1, 1.4.3-4.1+deb8u1 |
| — |
Debian:9(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libssh2 | 1.7.0-1 |
| — |
Weakness Classification(2)
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 11× 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 97 of 184 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. 3 repeat rows among the latest 100 are merged into the row they repeat. The 87 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-23 16:27 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-22 16:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-21 17:39 UTCEG score recompute
- 2026-10-21 17:39 UTCVendor advisory
- 2026-10-21 17:39 UTCGHSA enrichmentGHSA-mq4f-qjqv-2ff5 · GitHub severity HIGH · GitHub CVSS 8.8
- 2026-10-21 16:27 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-20 16:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-19 16:27 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-18 16:27 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-18 09:45 UTCEG score recompute
- 2026-10-17 16:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-16 16:32 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-15 16:27 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-14 16:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-14 07:26 UTCVendor advisory
- 2026-10-14 07:26 UTCGHSA enrichmentGHSA-mq4f-qjqv-2ff5 · GitHub severity HIGH · GitHub CVSS 8.8
- 2026-10-14 07:02 UTCEG score recompute
- 2026-10-14 07:02 UTCVendor advisory
- 2026-10-14 07:02 UTCGHSA enrichmentGHSA-mq4f-qjqv-2ff5 · GitHub severity HIGH · GitHub CVSS 8.8
- 2026-10-13 16:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-12 19:54 UTCEG score recompute
- 2026-10-12 16:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-12 00:18 UTCEG score recompute
- 2026-10-11 13:42 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-10 19:56 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
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- 2026-10-09 20:03 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-08 16:37 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-07 23:43 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-06 15:13 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-05 17:39 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-10-03 14:22 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-30 14:59 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-30 10:23 UTCEG score recompute
- 2026-09-28 13:46 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-28 12:08 UTCOSV refresh
- 2026-09-27 13:40 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-26 15:54 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-26 00:20 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-24 13:59 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-22 14:43 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-21 20:28 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-20 20:11 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-19 15:37 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-18 19:23 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-17 19:22 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-16 14:04 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-15 03:06 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-13 16:42 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-12 14:56 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-11 14:48 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-11 09:32 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-08 21:55 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-09-08 15:34 UTCOSV refresh
- 2026-09-07 15:57 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-09-06 13:44 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-09-05 15:24 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-09-04 13:56 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-09-02 14:08 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-09-01 03:32 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-30 01:18 UTCEPSS rescoreEPSS 6.1% · 93rd percentile
- 2026-08-27 14:21 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-26 14:42 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-25 13:45 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-22 01:41 UTCOSV refresh
- 2026-08-19 17:00 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-18 13:44 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-17 13:43 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-15 01:26 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-13 21:57 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-12 13:47 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-09 13:43 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-08 16:33 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-07 16:23 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-06 05:54 UTCOSV refresh
- 2026-08-05 19:13 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-04 15:05 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-08-04 10:34 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
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- 2026-07-30 16:24 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
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- 2026-07-28 15:32 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-26 14:51 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-25 14:14 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-24 14:14 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-23 14:15 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-23 01:45 UTCEG score recompute
- 2026-07-22 22:26 UTCEG score recompute
- 2026-07-22 14:05 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-21 15:22 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-20 20:02 UTCOSV refresh
- 2026-07-20 17:04 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-19 14:28 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-19 02:26 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-18 10:02 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
- 2026-07-16 16:59 UTCEPSS rescoreEPSS 6.1% · 92nd percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownAlpine:v3.10:libssh2
- CVE-2019-3861EG 9.1EPSS p92CRITICAL
- CVE-2019-3860EG 9.1EPSS p93CRITICAL
- CVE-2019-3858EG 9.1EPSS p94CRITICAL
- CVE-2019-3862EG 9.1EPSS p95CRITICAL
- CVE-2019-3859EG 9.1EPSS p94CRITICAL
- CVE-2019-3856EG 8.8EPSS p93HIGH
- CVE-2019-3863EG 8.8HIGH
- CVE-2019-3855EG 8.8EPSS p95HIGH
- CVE-2019-17498EG 8.1EPSS p90HIGH
- CVE-2019-13115EG 8.1EPSS p96HIGH
Same vendor
10 shownredhat:RHSA-2019:0679 · redhat:RHSA-2019:1175 · ubuntu:USN-5308-1
- CVE-2019-3856EG 8.8EPSS p93HIGH
- CVE-2019-3863EG 8.8HIGH
- CVE-2019-3855EG 8.8EPSS p95HIGH
- CVE-2018-20815EG 9.8EPSS p91CRITICAL
- CVE-2019-3861EG 9.1EPSS p92CRITICAL
- CVE-2019-3860EG 9.1EPSS p93CRITICAL
- CVE-2019-3858EG 9.1EPSS p94CRITICAL
- CVE-2019-3862EG 9.1EPSS p95CRITICAL
- CVE-2019-3859EG 9.1EPSS p94CRITICAL
- CVE-2019-17498EG 8.1EPSS p90HIGH
Same CWE
10 shownCWE-190 · CWE-787
Frequently asked(5)
What is CVE-2019-3857?
When was the CVE record for CVE-2019-3857 published?
Is CVE-2019-3857 actively exploited?
What is the CVSS score of CVE-2019-3857?
How do I remediate CVE-2019-3857?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2019-3857
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