CVE-2026-39956

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 95% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.1Exploit: NoneExposed: 0

A fix is available — apply it.

jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the _strindices builtin in jq's src/builtin.c passes its arguments directly to jv_string_indexes() without verifying they are strings, and jv_string_indexes() in src/jv.c relies solely on assert() checks that are stripped in release builds compiled with -DNDEBUG. This allows an attacker to crash jq trivially with input like _strindices(0), and by crafting a numeric value whose IEEE-754 bit pattern maps to a chosen pointer, achieve a controlled pointer dereference and limited memory read/probe primitive. Any deployment that evaluates untrusted jq filters against a release build is vulnerable. This issue has been patched in commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03.

CVSS v3
6.1
EG Score
6.1(medium)
EPSS
7.1%
KEV
Not listed

Published

April 13, 2026

Last Modified

April 21, 2026

References (3)

Vendor Advisories for CVE-2026-39956(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntujq (1.5+dfsg-1ubuntu0.1+esm4) @ xenial2026-06-14ubuntu
ubuntulibjq1 (1.8.1-4ubuntu2) @ resolute2026-06-14ubuntu
redhatjq-main-1.8.1-3.hum12026-04-16redhat

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.

Weakness Classification(3)

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

Additional Vendor Advisories

(2)

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 9× in last 7d / 36× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-07-16 17:03 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 02:00 UTCEPSS rescore
  5. 2026-07-13 22:30 UTCEPSS rescore
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-12 05:46 UTCEPSS rescore
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-09 19:10 UTCEPSS rescore
  11. 2026-07-08 15:15 UTCEPSS rescore
  12. 2026-07-07 13:46 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-05 02:30 UTCEPSS rescore
  18. 2026-07-04 06:31 UTCEPSS rescore
  19. 2026-07-01 15:06 UTCEPSS rescore
  20. 2026-06-30 23:22 UTCEPSS rescore
  21. 2026-06-29 14:06 UTCEPSS rescore
  22. 2026-06-28 14:07 UTCEPSS rescore
  23. 2026-06-28 04:56 UTCEPSS rescore
  24. 2026-06-27 03:08 UTCEPSS rescore
  25. 2026-06-25 13:49 UTCEPSS rescore
Show 66 more
  1. 2026-06-25 13:49 UTCEPSS rescore
  2. 2026-06-24 14:05 UTCEPSS rescore
  3. 2026-06-23 21:33 UTCEPSS rescore
  4. 2026-06-22 14:25 UTCEPSS rescore
  5. 2026-06-22 14:25 UTCEPSS rescore
  6. 2026-06-21 14:56 UTCEPSS rescore
  7. 2026-06-21 14:56 UTCEPSS rescore
  8. 2026-06-21 01:59 UTCEPSS rescore
  9. 2026-06-19 19:25 UTCEPSS rescore
  10. 2026-06-18 17:52 UTCEPSS rescore
  11. 2026-06-18 17:52 UTCEPSS rescore
  12. 2026-06-17 17:53 UTCEPSS rescore
  13. 2026-06-16 17:52 UTCEPSS rescore
  14. 2026-06-15 17:49 UTCEPSS rescore
  15. 2026-06-14 23:18 UTCEPSS rescore
  16. 2026-06-14 21:38 UTCVendor advisory
  17. 2026-06-13 23:00 UTCEPSS rescore
  18. 2026-06-12 23:12 UTCEPSS rescore
  19. 2026-06-12 23:12 UTCEPSS rescore
  20. 2026-06-11 19:34 UTCVendor advisory
  21. 2026-06-11 14:00 UTCEPSS rescore
  22. 2026-06-10 22:18 UTCEPSS rescore
  23. 2026-06-10 13:22 UTCEPSS rescore
  24. 2026-06-10 12:44 UTCVendor advisory
  25. 2026-06-09 11:05 UTCVendor advisory
  26. 2026-06-08 14:17 UTCEPSS rescore
  27. 2026-06-08 14:17 UTCEPSS rescore
  28. 2026-06-08 08:04 UTCVendor advisory
  29. 2026-06-07 15:25 UTCEPSS rescore
  30. 2026-06-07 15:25 UTCEPSS rescore
  31. 2026-06-07 15:25 UTCEPSS rescore
  32. 2026-06-07 06:25 UTCVendor advisory
  33. 2026-06-06 13:47 UTCEPSS rescore
  34. 2026-06-06 13:47 UTCEPSS rescore
  35. 2026-06-05 22:47 UTCEPSS rescore
  36. 2026-06-05 22:47 UTCEPSS rescore
  37. 2026-06-04 13:12 UTCEPSS rescore
  38. 2026-06-04 13:12 UTCEPSS rescore
  39. 2026-06-02 22:38 UTCVendor advisory
  40. 2026-06-02 20:13 UTCEPSS rescore
  41. 2026-06-01 20:59 UTCVendor advisory
  42. 2026-06-01 13:52 UTCEPSS rescore
  43. 2026-06-01 13:52 UTCEPSS rescore
  44. 2026-06-01 13:51 UTCEPSS rescore
  45. 2026-05-31 22:30 UTCEPSS rescore
  46. 2026-05-31 22:30 UTCEPSS rescore
  47. 2026-05-31 00:16 UTCEPSS rescore
  48. 2026-05-31 00:16 UTCEPSS rescore
  49. 2026-05-31 00:16 UTCEPSS rescore
  50. 2026-05-29 13:44 UTCEPSS rescore
  51. 2026-05-29 13:44 UTCEPSS rescore
  52. 2026-05-28 13:44 UTCEPSS rescore
  53. 2026-05-28 13:44 UTCEPSS rescore
  54. 2026-05-28 13:44 UTCEPSS rescore
  55. 2026-05-27 13:40 UTCEPSS rescore
  56. 2026-05-27 13:40 UTCEPSS rescore
  57. 2026-05-27 13:40 UTCEPSS rescore
  58. 2026-05-26 13:44 UTCEPSS rescore
  59. 2026-05-26 07:18 UTCEPSS rescore
  60. 2026-05-26 07:18 UTCEPSS rescore
  61. 2026-05-20 22:38 UTCEPSS rescore
  62. 2026-05-20 22:38 UTCEPSS rescore
  63. 2026-05-20 17:32 UTCEG score recompute
  64. 2026-05-20 17:32 UTCVendor advisory
  65. 2026-05-20 11:22 UTCEPSS rescore
  66. 2026-05-20 11:22 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-39956?
CVE-2026-39956 is a medium vulnerability published on April 13, 2026. jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the strindices builtin in jq's src/builtin.c passes its arguments directly to jvstringindexes() without verifying they are strings, and jvstringindexes() in src/jv.c relies solely on assert() checks that…
When was CVE-2026-39956 disclosed?
CVE-2026-39956 was first published in the National Vulnerability Database on April 13, 2026, with the most recent update on April 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-39956 actively exploited?
CVE-2026-39956 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 7.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-39956?
CVE-2026-39956 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-39956?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39956, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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