Unsigned integer underflow in wstrncat() in src/port.c in wolfSSL wolfSSH from v1.4.11 through v1.5.0 on non-Windows platforms allows an authenticated remote attacker to write one out-of-bounds null byte past the end of a stack buffer by sending a crafted SFTP path. wolfSSH_RealPath() in src/ssh.c appends each path component with a remaining-size bound (outSz - curSz) rather than the full destination size, so once the accumulated path reaches half the output buffer the size_t computation n - strlen(s1) - 1 wraps to near SIZE_MAX. The strncat() call is then effectively unbounded and copies the whole component; when that component exactly fills the remainder of the buffer, its terminating null is written one byte past the end. The caller's own length check keeps the copied data inside the buffer, so the overflow is limited to that single null byte, which may corrupt an adjacent stack value and crash the process. Applications that call the public wolfSSH_RealPath() with an output buffer smaller than the input path are additionally exposed to an unbounded copy, because the word32 expression outSz - segSz in that length check also wraps.
CVE-2026-83742
“—” beside the score: it is equal to NVD's CVSS score.
Score 8.8 from GitHub Security Advisory published 2026-10-07. NVD baseline CVSS 8.8; sources differ by 0.0.
Also known asEUVD-2026-94164 (ENISA EUVD) · GHSA-4ff8-whrv-3wcm (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.8
- EG Score
- 8.8HIGHhigh confidence
- EG Risk
- 40EG Risk 40/100
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.Exploitation0.4% × 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 every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (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. - EPSS PROB
- 0.4%
- EPSS %ILE
- 37th
- 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
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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
October 7, 2026
Last Modified
October 13, 2026
Advisory Details (4)
Auto-updated Oct 7, 2026commit fbc7cd88a23b (wolfSSL/wolfssh)
Patch available: wolfSSL/wolfssh v1.6.0-stable (contains commit fbc7cd88a23b)
https://github.com/wolfSSL/wolfssh/commit/fbc7cd88a23b59a45a584020a4c7242d9bd70f35commit 513e52b18927 (wolfSSL/wolfssh)
Patch available: wolfSSL/wolfssh v1.6.0-stable (contains commit 513e52b18927)
https://github.com/wolfSSL/wolfssh/commit/513e52b18927a4e3f7cf17ecaf107958e56139decommit 822e4464560b (wolfSSL/wolfssh)
Patch available: wolfSSL/wolfssh v1.6.0-stable (contains commit 822e4464560b)
https://github.com/wolfSSL/wolfssh/commit/822e4464560b467580ea37a2fc03b0988d88b71fFix multiple reported issues
Patch available: wolfSSL/wolfssh v1.6.0-stable (PR #1084 merged 2026-07-16)
https://github.com/wolfSSL/wolfssh/pull/1084Vendor Advisories for CVE-2026-83742(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 56× 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.
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-27 21:10 UTCEG score recompute
- 2026-10-27 21:10 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm · GitHub CVSS 8.8
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-10-25 13:56 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-10-20 18:02 UTCEG score recompute
- 2026-10-20 18:02 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm · GitHub CVSS 8.8
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-18 03:07 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 31st percentile
Show 31 moreShow fewer
- 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-13 14:47 UTCEG score recompute▲ 3.50
- 2026-10-13 14:46 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-13 14:44 UTCNVD updateCVSS v3 → 8.8 · severity → HIGH
- 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-12 14:54 UTCEG score recompute
- 2026-10-11 19:19 UTCEG score recompute
- 2026-10-11 16:35 UTCEG score recompute
- 2026-10-11 13:53 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-11 12:32 UTCEG score recompute
- 2026-10-11 12:32 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-10 13:29 UTCEG score recompute
- 2026-10-10 13:29 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-09 14:24 UTCEG score recompute
- 2026-10-09 14:24 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-08 15:18 UTCEG score recompute
- 2026-10-08 15:18 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 24th percentile
- 2026-10-07 16:15 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-07 12:21 UTCEG score recompute
- 2026-10-07 12:21 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-07 11:38 UTCEG score recompute
- 2026-10-07 11:37 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-07 03:31 UTCEG score recompute
- 2026-10-07 03:31 UTCGHSA enrichmentGHSA-4ff8-whrv-3wcm
- 2026-10-07 03:02 UTCEG score recomputeFirst assessed: 5.3 MEDIUM
- 2026-10-07 03:01 UTCMITRE cvelistV5first tracked
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Frequently asked(5)
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-83742
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