CVE-2026-87823

HIGHPre-NVD 8.28.2
EchelonGraph scoreMEDIUM confidence

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

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-09-09. A secondary CVSS source baseline 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-75021 (ENISA EUVD) · GHSA-cm3p-487m-cmvq (GitHub Security Advisories)Source: ENISA EUVD

8.2EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.2Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

zstd-jni before 1.5.7-14 performs 32-bit signed bounds checks on three direct-ByteBuffer frame-size native methods, allowing out-of-bounds memory reads via negative or overflowing offsets. Attackers can supply negative offset values near Integer.MIN_VALUE to read unmapped memory, causing JVM termination or extracting arbitrary frame size data from unintended memory locations.

CVSS v3
8.2
EG Score
8.2HIGHmedium confidence
EG Risk
68
EG Risk 68/100

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)
Severity82% × 45%
Impact severity (EG Severity): CVSS 8.2 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 public PoC (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
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 (8.2): severity, escalated by confirmed exploitation. This CVE's 8.2 is its impact severity (EG Severity), not escalated.

EG Severity
8.2 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 2026-11-02). 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, and whom BOD 26-04 binds: 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 public PoC (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.

The score's inputs: 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 9, 2026

Last Modified

September 9, 2026

Advisory Details (7)

Auto-updated Sep 9, 2026
Patch available. Sources: github, github_commit.
Web page

zstd-jni 1.1.1 through 1.5.7-13 Out-of-Bounds Read via Direct ByteBuffer Frame-Size Methods | Advisories | VulnCheck

https://www.vulncheck.com/advisories/zstd-jni-1.1.1-through-1.5.7-13-out-of-bounds-read-via-direct-bytebuffer-frame-size-methods
Web page

GitHub - luben/zstd-jni: JNI binding for Zstd · GitHub

https://github.com/luben/zstd-jni
GitHub commit

commit 46dcb2a54c8b (luben/zstd-jni)

Fix landed in luben/zstd-jni commit 46dcb2a54c8b — awaiting tagged release

https://github.com/luben/zstd-jni/commit/46dcb2a54c8b8f2ce2cad7187a7513f509c533ac
Web page

zstd-jni/src/main/java/com/github/luben/zstd/Zstd.java at v1.5.7-13 · luben/zstd-jni · GitHub

https://github.com/luben/zstd-jni/blob/v1.5.7-13/src/main/java/com/github/luben/zstd/Zstd.java
Web page

zstd-jni/src/main/native/jni_zstd.c at v1.5.7-13 · luben/zstd-jni · GitHub

https://github.com/luben/zstd-jni/blob/v1.5.7-13/src/main/native/jni_zstd.c
GitHub commit

commit d7a1c99322d5 (luben/zstd-jni)

Fix landed in luben/zstd-jni commit d7a1c99322d5 — awaiting tagged release

https://github.com/luben/zstd-jni/commit/d7a1c99322d5e1fc71932e722c0b5bb2fc525d3f
GitHub advisoryMentions a patch (unverified)

Integer Overflow Bypasses Bounds Check on Direct ByteBuffer Frame-Size Queries · Advisory · luben/zstd-jni · GitHub

https://github.com/luben/zstd-jni/security/advisories/GHSA-jfr6-9xqw-2g2q

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatzstd-jni2026-09-21redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
zstd-jni-java1.5.2-5+ds-3 ... 1.5.4-2+ds-3~exp4 (12 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
zstd-jni-java1.5.2-5+ds-7 ... 1.5.4-2+ds-3~exp4 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
zstd-jni-java1.5.2-5+ds-7 ... 1.5.4-2+ds-3~exp4 (8 versions)
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 67× 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 100 of 177 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. None are among the latest 100 rows. The 77 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-04 16:37 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  3. 2026-11-03 08:05 UTCEG score recompute
  4. 2026-11-03 08:05 UTCVendor advisory
  5. 2026-11-03 08:05 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  6. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  7. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  8. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  9. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  10. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  11. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  12. 2026-10-27 17:56 UTCEG score recompute
  13. 2026-10-27 17:56 UTCVendor advisory
  14. 2026-10-27 17:55 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  15. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  16. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  17. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-10-25 13:53 UTCEG score recompute
  19. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  21. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  23. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-10-19 19:17 UTCEG score recompute
  25. 2026-10-19 19:17 UTCVendor advisory
Show 75 more
  1. 2026-10-19 19:17 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  2. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-18 03:03 UTCEG score recompute
  5. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  7. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  8. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  9. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-10-13 05:05 UTCEG score recompute
  11. 2026-10-13 05:05 UTCVendor advisory
  12. 2026-10-13 05:05 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  13. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  14. 2026-10-12 14:49 UTCEG score recompute
  15. 2026-10-11 21:57 UTCVendor advisory
  16. 2026-10-11 21:57 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  17. 2026-10-11 19:16 UTCEG score recompute
  18. 2026-10-11 16:33 UTCEG score recompute
  19. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  20. 2026-10-11 13:49 UTCEG score recompute
  21. 2026-10-11 07:17 UTCEG score recompute
  22. 2026-10-11 07:17 UTCVendor advisory
  23. 2026-10-11 07:17 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  24. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-10-10 19:42 UTCVendor advisory
  26. 2026-10-10 19:42 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  27. 2026-10-10 08:18 UTCVendor advisory
  28. 2026-10-10 08:18 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  29. 2026-10-09 20:08 UTCEG score recompute
  30. 2026-10-09 20:08 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  31. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  32. 2026-10-08 23:59 UTCEG score recompute
  33. 2026-10-08 23:59 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  34. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  35. 2026-10-08 07:00 UTCEG score recompute
  36. 2026-10-08 07:00 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  37. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  38. 2026-10-07 20:00 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  39. 2026-10-07 05:24 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  40. 2026-10-06 18:24 UTCEG score recompute
  41. 2026-10-06 18:24 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  42. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  43. 2026-10-06 07:24 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  44. 2026-10-05 20:24 UTCEG score recompute
  45. 2026-10-05 20:24 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  46. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  47. 2026-10-05 09:21 UTCEG score recompute
  48. 2026-10-05 09:21 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  49. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  50. 2026-10-04 22:22 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  51. 2026-10-04 11:22 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  52. 2026-10-04 00:22 UTCEG score recompute
  53. 2026-10-04 00:22 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  54. 2026-10-03 12:11 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  55. 2026-10-03 00:11 UTCEG score recompute
  56. 2026-10-03 00:11 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  57. 2026-10-02 12:37 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  58. 2026-10-02 00:24 UTCEG score recompute
  59. 2026-10-02 00:24 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  60. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  61. 2026-10-01 12:07 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  62. 2026-10-01 01:07 UTCEG score recompute
  63. 2026-10-01 01:07 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  64. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  65. 2026-09-30 14:08 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  66. 2026-09-30 02:02 UTCEG score recompute
  67. 2026-09-30 02:02 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  68. 2026-09-29 14:52 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  69. 2026-09-29 03:51 UTCEG score recompute
  70. 2026-09-29 03:51 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  71. 2026-09-28 16:51 UTCEG score recompute
  72. 2026-09-28 16:50 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  73. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  74. 2026-09-28 05:50 UTCGHSA enrichmentGHSA-cm3p-487m-cmvq · GitHub severity HIGH · GitHub CVSS 8.2
  75. 2026-09-27 18:51 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-87823?
CVE-2026-87823 is a high-severity vulnerability; its CVE record was published on September 9, 2026. zstd-jni before 1.5.7-14 performs 32-bit signed bounds checks on three direct-ByteBuffer frame-size native methods, allowing out-of-bounds memory reads via negative or overflowing offsets. Attackers can supply negative offset values near Integer.MIN_VALUE to read unmapped memory, causing JVM…
When was CVE-2026-87823 made public?
CVE-2026-87823 was made public on August 19, 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 September 9, 2026. EchelonGraph's copy of the record carries a last-modified date of September 9, 2026; the record at its source may have been updated since.
Is CVE-2026-87823 actively exploited?
CVE-2026-87823 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-87823?
CVE-2026-87823 has a CVSS base score of 8.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-87823?
A fix for CVE-2026-87823 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-87823 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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