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
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
39%
KEV
Not listed

Published

May 14, 2026

Last Modified

August 25, 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
redhatrhui5/rhua-tp-rhel9:17872412602026-08-24redhat
redhatdiscovery/discovery-server-rhel9:17866385732026-08-13redhat
redhatlibpq-0:13.23-1.el9_6.12026-08-05redhat
redhatlibpq-0:16.14-0.el10_0.12026-08-05redhat
redhatlibpq-0:13.23-1.el9_2.12026-08-04redhat
redhatlibpq-0:13.23-1.el9_4.12026-08-04redhat
redhatpostgresql-0:9.2.24-9.el7_9.62026-08-03redhat
redhatlibpq-0:13.23-1.el8_6.12026-07-28redhat
redhatlibpq-0:13.23-3.el9_82026-07-23redhat
redhatrhui5/rhua-rhel9:17847950762026-07-23redhat
redhatlibpq-0:16.14-1.el10_22026-07-23redhat
redhatlibpq-0:13.23-1.el8_4.12026-07-23redhat
redhatpostgresql:13-8080020260709122729.63b345852026-07-21redhat
redhatlibpq-0:13.23-1.el8_8.12026-07-06redhat
redhatpostgresql:13-8040020260630100922.522a0ee42026-07-01redhat
redhatpostgresql:12-8040020260624104459.522a0ee42026-07-01redhat
redhatpostgresql:12-8080020260626093604.63b345852026-07-01redhat
redhatpostgresql:15-9040020260616071806.rhel92026-06-30redhat
redhatpostgresql:15-9020020260625101129.rhel92026-06-30redhat
redhatpostgresql:13-8060020260625065744.ad008a3a2026-06-29redhat
redhatpostgresql:15-9060020260622062902.rhel92026-06-29redhat
redhatpostgresql-0:13.23-1.el9_4.22026-06-25redhat
redhatpostgresql:12-8060020260623094704.ad008a3a2026-06-25redhat
redhatpostgresql-0:13.23-1.el9_6.22026-06-25redhat
redhatpostgresql-0:13.23-1.el9_2.22026-06-25redhat
redhatpostgresql:12-8100020260605152253.489197e62026-06-24redhat
redhatpostgresql:13-8100020260605152256.489197e62026-06-23redhat
redhatpostgresql:16-8100020260530205218.489197e62026-06-23redhat
redhatpostgresql:15-9080020260605124405.rhel92026-06-22redhat
redhatpostgresql18-0:18.4-1.el10_22026-06-22redhat

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

(14 across 9 ecosystems)
Alpine:v3.20(2)
PackageVulnerable rangeFixed inDependents
postgresql15—15.18-r0—
postgresql16—16.14-r0—
Alpine:v3.21(2)
PackageVulnerable rangeFixed inDependents
postgresql16—16.14-r0—
postgresql17—17.10-r0—
Alpine:v3.22(2)
PackageVulnerable rangeFixed inDependents
postgresql16—16.14-r0—
postgresql17—17.10-r0—
Alpine:v3.23(2)
PackageVulnerable rangeFixed inDependents
postgresql17—17.10-r0—
postgresql18—18.4-r0—
Alpine:v3.24(2)
PackageVulnerable rangeFixed inDependents
postgresql17—17.10-r0—
postgresql18—18.4-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
postgresql-1313.10-0+deb11u1 ... 13.9-0+deb11u1 (25 versions)13.23-0+deb11u4—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
postgresql-1515.10-0+deb12u1 ... 15.9-0+deb12u1 (20 versions)15.18-0+deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
postgresql-1717.5-1 ... 17.9-0+deb13u1 (6 versions)17.10-0+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
postgresql-1818.0-1 ... 18~~devel.20250502-1 (19 versions)18.4-1—

Weakness Classification(2)

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

Additional Vendor Advisories

(22)

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 5× in last 7d / 38× 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 331 total refreshes for this CVE.

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

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 August 25, 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 61.2% 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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