CVE-2026-6477

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-14. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — Patch released this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

Use of inherently dangerous function PQfn(..., result_is_int=0, ...) in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response. Like gets(), PQfn(..., result_is_int=0, ...) stores arbitrary-length, server-determined data into a buffer of unspecified size. Because both the \lo_export command in psql and pg_dump call lo_read(), the server superuser can overwrite pg_dump or psql stack memory. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

May 14, 2026

Last Modified

July 24, 2026

Advisory Details (1)

Auto-updated May 14, 2026
No patch confirmed yet.
generic

PostgreSQL: CVE-2026-6477: PostgreSQL libpq lo_* functions let server superuser overwrite client stack memory

https://www.postgresql.org/support/security/CVE-2026-6477/

Vendor Advisories for CVE-2026-6477(20)

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

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatlibpq-0:16.14-1.el10_22026-07-23redhat
redhatlibpq-0:13.23-1.el8_4.12026-07-23redhat
redhatlibpq-0:13.23-3.el9_82026-07-23redhat
redhatrhui5/rhua-rhel9:17847950762026-07-23redhat
redhatpostgresql:13-8080020260709122729.63b345852026-07-21redhat
redhatlibpq-0:13.23-1.el8_8.12026-07-06redhat
redhatpostgresql:13-8040020260630100922.522a0ee42026-07-01redhat
redhatpostgresql:12-8080020260626093604.63b345852026-07-01redhat
redhatpostgresql:12-8040020260624104459.522a0ee42026-07-01redhat
redhatpostgresql:15-9040020260616071806.rhel92026-06-30redhat
redhatpostgresql:15-9020020260625101129.rhel92026-06-30redhat
redhatpostgresql:15-9060020260622062902.rhel92026-06-29redhat
redhatpostgresql:13-8060020260625065744.ad008a3a2026-06-29redhat
redhatpostgresql:12-8060020260623094704.ad008a3a2026-06-25redhat
redhatpostgresql-0:13.23-1.el9_4.22026-06-25redhat
redhatpostgresql-0:13.23-1.el9_2.22026-06-25redhat
redhatpostgresql-0:13.23-1.el9_6.22026-06-25redhat
redhatpostgresql:12-8100020260605152253.489197e62026-06-24redhat
redhatpostgresql:13-8100020260605152256.489197e62026-06-23redhat
redhatpostgresql:16-8100020260530205218.489197e62026-06-23redhat
redhatpostgresql-0:13.23-3.el9_82026-06-22redhat
redhatpostgresql:15-9080020260605124405.rhel92026-06-22redhat
redhatpostgresql18-0:18.4-1.el10_22026-06-22redhat
redhatlibpq-0:13.23-2.el8_102026-06-22redhat
redhatpostgresql16-0:16.14-1.el10_02026-06-22redhat
redhatpostgresql16-0:16.14-1.el10_22026-06-22redhat
redhatpostgresql:15-8080020260615085052.63b345852026-06-17redhat
redhatpostgresql:16-9060020260612084605.rhel92026-06-17redhat
redhatpostgresql:16-9040020260612132455.rhel92026-06-17redhat
redhatpostgresql:15-8100020260605152259.489197e62026-06-16redhat

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(2)

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

Additional Vendor Advisories

(15)

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 17× in last 7d / 55× 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.

Showing the most recent 100 of 181 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-6477?
CVE-2026-6477 is a high vulnerability published on May 14, 2026. Use of inherently dangerous function PQfn(..., resultisint=0, ...) in PostgreSQL libpq loexport(), loread(), lolseek64(), and lotell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response. Like gets(), PQfn(..., resultisint=0, ...) stores…
When was CVE-2026-6477 disclosed?
CVE-2026-6477 was first published in the National Vulnerability Database on May 14, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6477 actively exploited?
CVE-2026-6477 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 62.9% of all scored CVEs.
What is the CVSS score of CVE-2026-6477?
CVE-2026-6477 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-6477?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6477, 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.

Dependency Blast Radius

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