CVE-2026-39979

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 78% 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
Trending — 3 sources updated this weekElevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 6.5Exploit: NoneExposed: 0

A fix is available — apply it.

jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jv_parse_sized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-handling path formats the input buffer using %s in jv_string_fmt(), which reads until a NUL terminator is found rather than respecting the caller-supplied length. This means that when malformed JSON is passed in a non-NUL-terminated buffer, the error construction logic performs an out-of-bounds read past the end of the buffer. The vulnerability is reachable by any libjq consumer calling jv_parse_sized() with untrusted input, and depending on memory layout, can result in memory disclosure or process termination. The issue has been patched in commit 2f09060afab23fe9390cce7cb860b10416e1bf5f.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
42.8%
KEV
Not listed

Published

April 13, 2026

Last Modified

July 15, 2026

Advisory Details (10)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github, redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:18045
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:18044
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:18043
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:18042
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:18040
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:16693
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:16692
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:16252
github Patch Available🟡 PoC Available

Out-of-Bounds Read in jv_parse_sized() Error Formatting for Non-NUL-Terminated Counted Buffers · Advisory · jqlang/jq · GitHub

https://github.com/jqlang/jq/security/advisories/GHSA-2hhh-px8h-355p
github_commit

commit 2f09060afab2 (jqlang/jq)

Fix landed in jqlang/jq commit 2f09060afab2 — awaiting tagged release

https://github.com/jqlang/jq/commit/2f09060afab23fe9390cce7cb860b10416e1bf5f

Vendor Advisories for CVE-2026-39979(20)

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

Patch Availability(19)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibjq1 (1.8.1-4ubuntu2) @ resolute2026-06-14ubuntu
ubuntujq (1.3-1.1ubuntu1.1+esm4) @ trusty2026-06-14ubuntu
redhatrhcos-415.92.202606030318-02026-06-11redhat
redhatrhaiis/model-opt-cuda-rhel9:17806819842026-06-10redhat
redhatrhcos-4.19.9.6.202606031700-02026-06-10redhat
redhatjq-0:1.6-19.el9_8.22026-05-19redhat
redhatjq-0:1.7.1-11.el10_2.22026-05-19redhat
redhatjq-0:1.6-12.el9_0.32026-05-18redhat
redhatjq-0:1.5-12.el8_4.52026-05-18redhat
redhatjq-0:1.6-15.el9_2.32026-05-18redhat
redhatjq-0:1.6-16.el9_4.22026-05-18redhat
redhatjq-0:1.6-3.el8_6.22026-05-18redhat
redhatjq-0:1.7.1-8.el10_0.32026-05-18redhat
redhatjq-0:1.6-6.el8_8.42026-05-18redhat
redhatjq-0:1.6-17.el9_6.42026-05-18redhat
redhatjq-0:1.7.1-11.el10_1.0.22026-05-13redhat
redhatjq-0:1.6-19.el9_7.0.22026-05-13redhat
redhatjq-0:1.6-12.el8_102026-05-12redhat
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(1)

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

Additional Vendor Advisories

(10)

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 11× in last 7d / 40× 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 02:23 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  5. 2026-07-15 02:00 UTCEPSS rescore
  6. 2026-07-15 01:21 UTCMITRE cvelistV5CVSS v3 → 8.2 · severity → HIGH
  7. 2026-07-13 22:30 UTCEPSS rescore
  8. 2026-07-13 06:13 UTCEPSS rescore
  9. 2026-07-13 06:13 UTCEPSS rescore
  10. 2026-07-12 05:46 UTCEPSS rescore
  11. 2026-07-11 08:27 UTCEPSS rescore
  12. 2026-07-10 12:26 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  13. 2026-07-10 12:12 UTCMITRE cvelistV5CVSS v3 → 8.2 · severity → HIGH
  14. 2026-07-09 19:10 UTCEPSS rescore
  15. 2026-07-08 15:15 UTCEPSS rescore
  16. 2026-07-07 13:46 UTCEPSS rescore
  17. 2026-07-06 16:27 UTCEPSS rescore
  18. 2026-07-06 16:27 UTCEPSS rescore
  19. 2026-07-06 02:23 UTCEPSS rescore
  20. 2026-07-06 02:23 UTCEPSS rescore
  21. 2026-07-05 02:30 UTCEPSS rescore
  22. 2026-07-04 06:31 UTCEPSS rescore
  23. 2026-07-01 15:06 UTCEPSS rescore
  24. 2026-06-30 23:22 UTCEPSS rescore
  25. 2026-06-29 14:06 UTCEPSS rescore
Show 71 more
  1. 2026-06-28 14:07 UTCEPSS rescore
  2. 2026-06-28 04:56 UTCEPSS rescore
  3. 2026-06-27 03:08 UTCEPSS rescore
  4. 2026-06-25 13:49 UTCEPSS rescore
  5. 2026-06-25 13:49 UTCEPSS rescore
  6. 2026-06-24 14:05 UTCEPSS rescore
  7. 2026-06-23 21:33 UTCEPSS rescore
  8. 2026-06-22 14:25 UTCEPSS rescore
  9. 2026-06-22 14:25 UTCEPSS rescore
  10. 2026-06-21 14:56 UTCEPSS rescore
  11. 2026-06-21 14:56 UTCEPSS rescore
  12. 2026-06-21 01:59 UTCEPSS rescore
  13. 2026-06-19 19:25 UTCEPSS rescore
  14. 2026-06-18 17:52 UTCEPSS rescore
  15. 2026-06-18 17:52 UTCEPSS rescore
  16. 2026-06-17 17:53 UTCEPSS rescore
  17. 2026-06-16 17:52 UTCEPSS rescore
  18. 2026-06-15 17:49 UTCEPSS rescore
  19. 2026-06-14 23:18 UTCEPSS rescore
  20. 2026-06-14 21:37 UTCVendor advisory
  21. 2026-06-13 23:00 UTCEPSS rescore
  22. 2026-06-12 23:12 UTCEPSS rescore
  23. 2026-06-12 23:12 UTCEPSS rescore
  24. 2026-06-11 19:34 UTCVendor advisory
  25. 2026-06-11 14:00 UTCEPSS rescore
  26. 2026-06-10 22:18 UTCEPSS rescore
  27. 2026-06-10 13:22 UTCEPSS rescore
  28. 2026-06-10 12:16 UTCVendor advisory
  29. 2026-06-09 11:05 UTCVendor advisory
  30. 2026-06-08 14:17 UTCEPSS rescore
  31. 2026-06-08 14:17 UTCEPSS rescore
  32. 2026-06-08 07:32 UTCVendor advisory
  33. 2026-06-07 15:25 UTCEPSS rescore
  34. 2026-06-07 15:25 UTCEPSS rescore
  35. 2026-06-07 15:25 UTCEPSS rescore
  36. 2026-06-07 06:25 UTCVendor advisory
  37. 2026-06-06 13:47 UTCEPSS rescore
  38. 2026-06-06 13:47 UTCEPSS rescore
  39. 2026-06-05 22:47 UTCEPSS rescore
  40. 2026-06-05 22:47 UTCEPSS rescore
  41. 2026-06-05 06:10 UTCEPSS rescore
  42. 2026-06-05 06:10 UTCEPSS rescore
  43. 2026-06-04 13:12 UTCEPSS rescore
  44. 2026-06-04 13:12 UTCEPSS rescore
  45. 2026-06-02 22:07 UTCVendor advisory
  46. 2026-06-02 20:13 UTCEPSS rescore
  47. 2026-06-01 20:59 UTCVendor advisory
  48. 2026-06-01 13:52 UTCEPSS rescore
  49. 2026-06-01 13:52 UTCEPSS rescore
  50. 2026-06-01 13:51 UTCEPSS rescore
  51. 2026-05-31 22:30 UTCEPSS rescore
  52. 2026-05-31 22:30 UTCEPSS rescore
  53. 2026-05-31 00:16 UTCEPSS rescore
  54. 2026-05-31 00:16 UTCEPSS rescore
  55. 2026-05-31 00:16 UTCEPSS rescore
  56. 2026-05-29 13:44 UTCEPSS rescore
  57. 2026-05-29 13:44 UTCEPSS rescore
  58. 2026-05-28 13:44 UTCEPSS rescore
  59. 2026-05-28 13:44 UTCEPSS rescore
  60. 2026-05-28 13:44 UTCEPSS rescore
  61. 2026-05-27 13:40 UTCEPSS rescore
  62. 2026-05-27 13:40 UTCEPSS rescore
  63. 2026-05-27 13:40 UTCEPSS rescore
  64. 2026-05-26 07:18 UTCEPSS rescore
  65. 2026-05-26 07:18 UTCEPSS rescore
  66. 2026-05-20 22:38 UTCEPSS rescore
  67. 2026-05-20 22:38 UTCEPSS rescore
  68. 2026-05-20 17:32 UTCEG score recompute
  69. 2026-05-20 17:32 UTCVendor advisory
  70. 2026-05-20 11:22 UTCEPSS rescore
  71. 2026-05-20 11:22 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-39979?
CVE-2026-39979 is a medium vulnerability published on April 13, 2026. jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the jvparsesized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-handling path formats the input buffer using %s in jvstringfmt(), which reads until a NUL…
When was CVE-2026-39979 disclosed?
CVE-2026-39979 was first published in the National Vulnerability Database on April 13, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-39979 actively exploited?
CVE-2026-39979 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 42.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-39979?
CVE-2026-39979 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-39979?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39979, 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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