CVE-2026-109395

CRITICALPre-NVD 9.19.1
EchelonGraph scoreHIGH confidence

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

Score 9.1 from GitHub Security Advisory (severity: HIGH) published 2026-10-20. A secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-104679 (ENISA EUVD) · GHSA-7xjc-8h6q-2f5h (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan mitigationRemediate 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: 0.5%CVSS: 9.1Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

Ning compress-lzf before 1.2.0 contains an out-of-bounds memory access vulnerability in the sun.misc.Unsafe based UnsafeChunkDecoder that fails to validate back-references and literal runs. Attackers can supply crafted LZF streams to applications using the default LZFDecoder to leak unrelated JVM heap memory into decompressed output or crash the JVM.

CVSS v3
9.1
EG Score
9.1CRITICALhigh confidence
EG Risk
56
EG Risk 56/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 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: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
EPSS PROB
0.5%
EPSS %ILE
44th
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-30). 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).

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.

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

October 20, 2026

Last Modified

October 20, 2026

Advisory Details (6)

Auto-updated Oct 20, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
Web page

Ning compress-lzf before 1.2.0 Out-of-Bounds Memory Access via UnsafeChunkDecoder | Advisories | VulnCheck

https://www.vulncheck.com/advisories/ning-compress-lzf-before-1.2.0-out-of-bounds-memory-access-via-unsafechunkdecoder
GitHub pull request

Improve bounds checks

Fix merged in ning/compress PR #68 on 2025-12-21 — awaiting tagged release

https://github.com/ning/compress/pull/68
GitHub commit

commit 06bdc3744a96 (ning/compress)

Fix landed in ning/compress commit 06bdc3744a96 — awaiting tagged release

https://github.com/ning/compress/commit/06bdc3744a96b736a7118891f403e44c664f108b
Web page

compress/src/main/java/com/ning/compress/lzf/impl/UnsafeChunkDecoder.java at compress-lzf-1.1.3 · ning/compress · GitHub

https://github.com/ning/compress/blob/compress-lzf-1.1.3/src/main/java/com/ning/compress/lzf/impl/UnsafeChunkDecoder.java#L104
Web page

GitHub - ning/compress: High-performance, streaming/chunking Java LZF codec, compatible with standard C LZF package · GitHub

https://github.com/ning/compress
Web page

Creating security advisory and requesting CVE through fork? (or alternatives) · github securitylab · Discussion #970 · GitHub

https://github.com/github/securitylab/discussions/970

Vendor Advisories for CVE-2026-109395(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 23× in last 7d / 42× 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.

  1. 2026-10-31 12:50 UTCEG score recompute
  2. 2026-10-31 12:49 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  3. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  4. 2026-10-30 12:50 UTCEG score recompute
  5. 2026-10-30 12:50 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  6. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  7. 2026-10-29 12:47 UTCEG score recompute
  8. 2026-10-29 12:47 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  9. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  10. 2026-10-28 12:48 UTCEG score recompute
  11. 2026-10-28 12:48 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  12. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  13. 2026-10-27 12:49 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  14. 2026-10-26 23:57 UTCEG score recompute
  15. 2026-10-26 23:57 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  16. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  17. 2026-10-25 20:22 UTCEG score recompute
  18. 2026-10-25 20:22 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  19. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  20. 2026-10-25 14:53 UTCEG score recompute
  21. 2026-10-24 20:22 UTCEG score recompute
  22. 2026-10-24 20:22 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  23. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  24. 2026-10-23 20:23 UTCEG score recompute
  25. 2026-10-23 20:23 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
Show 17 more
  1. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  2. 2026-10-22 20:23 UTCEG score recompute
  3. 2026-10-22 20:23 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  4. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  5. 2026-10-21 20:24 UTCEG score recompute
  6. 2026-10-21 20:24 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  7. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  8. 2026-10-20 20:26 UTCEG score recompute
  9. 2026-10-20 20:26 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  10. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  11. 2026-10-20 15:26 UTCEG score recompute
  12. 2026-10-20 15:26 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  13. 2026-10-20 14:41 UTCEG score recompute
  14. 2026-10-20 14:40 UTCGHSA enrichmentGHSA-7xjc-8h6q-2f5h · GitHub severity HIGH · GitHub CVSS 9.1
  15. 2026-10-20 01:26 UTCEG score recompute
  16. 2026-10-20 01:10 UTCEG score recomputeFirst assessed: 9.1 CRITICAL
  17. 2026-10-20 01:07 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-109395?
CVE-2026-109395 is a critical-severity vulnerability; its CVE record was published on October 20, 2026. Ning compress-lzf before 1.2.0 contains an out-of-bounds memory access vulnerability in the sun.misc.Unsafe based UnsafeChunkDecoder that fails to validate back-references and literal runs. Attackers can supply crafted LZF streams to applications using the default LZFDecoder to leak unrelated JVM…
When was CVE-2026-109395 made public?
CVE-2026-109395 was made public on October 7, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on October 20, 2026. EchelonGraph's copy of the record carries a last-modified date of October 20, 2026; the record at its source may have been updated since.
Is CVE-2026-109395 actively exploited?
CVE-2026-109395 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (44th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-109395?
CVE-2026-109395 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-109395?
An upstream fix for CVE-2026-109395 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-109395 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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