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
Elevated

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
38th
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 2026-11-09). 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 ... 1.5.7-23+ds-2 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
zstd-jni-java1.5.2-5+ds-7 ... 1.5.7-23+ds-2 (10 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 up to 1.5.7-23+ds-1: fixed in 1.5.7-23+ds-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 38× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 189 rows 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 89 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

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

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 (38th 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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