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
38%
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 20× in last 7d / 131× 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 312 total refreshes for this CVE.

  1. 2026-08-25 13:49 UTCEPSS rescore
  2. 2026-08-25 13:24 UTCEG score recompute
  3. 2026-08-25 13:24 UTCVendor advisory
  4. 2026-08-25 13:24 UTCGHSA enrichment
  5. 2026-08-25 12:20 UTCEG score recompute
  6. 2026-08-25 12:20 UTCVendor advisory
  7. 2026-08-25 12:20 UTCGHSA enrichment
  8. 2026-08-23 17:41 UTCEG score recompute
  9. 2026-08-23 17:41 UTCVendor advisory
  10. 2026-08-23 17:41 UTCGHSA enrichment
  11. 2026-08-23 00:19 UTCEPSS rescore
  12. 2026-08-22 01:52 UTCEG score recompute
  13. 2026-08-22 01:52 UTCVendor advisory
  14. 2026-08-22 01:52 UTCGHSA enrichment
  15. 2026-08-21 23:49 UTCEPSS rescore
  16. 2026-08-20 22:56 UTCEPSS rescore
  17. 2026-08-20 19:40 UTCEG score recompute
  18. 2026-08-20 19:40 UTCVendor advisory
  19. 2026-08-20 19:40 UTCGHSA enrichment
  20. 2026-08-19 17:04 UTCEPSS rescore
  21. 2026-08-18 13:49 UTCEPSS rescore
  22. 2026-08-18 13:49 UTCEPSS rescore
  23. 2026-08-17 13:47 UTCEPSS rescore
  24. 2026-08-17 10:26 UTCEG score recompute
  25. 2026-08-17 10:26 UTCVendor advisory
Show 75 more
  1. 2026-08-17 10:26 UTCGHSA enrichment
  2. 2026-08-16 14:56 UTCEPSS rescore
  3. 2026-08-16 14:56 UTCEPSS rescore
  4. 2026-08-16 03:58 UTCEG score recompute
  5. 2026-08-16 03:58 UTCVendor advisory
  6. 2026-08-16 03:58 UTCGHSA enrichment
  7. 2026-08-16 02:15 UTCEPSS rescore
  8. 2026-08-15 01:31 UTCEPSS rescore
  9. 2026-08-15 00:30 UTCVendor advisory
  10. 2026-08-15 00:30 UTCGHSA enrichment
  11. 2026-08-14 13:27 UTCEG score recompute
  12. 2026-08-14 13:27 UTCVendor advisory
  13. 2026-08-14 13:27 UTCGHSA enrichment
  14. 2026-08-14 12:29 UTCEG score recompute
  15. 2026-08-14 12:29 UTCVendor advisory
  16. 2026-08-14 12:29 UTCGHSA enrichment
  17. 2026-08-14 02:26 UTCEG score recompute
  18. 2026-08-14 02:26 UTCVendor advisory
  19. 2026-08-14 02:26 UTCGHSA enrichment
  20. 2026-08-13 22:00 UTCEPSS rescore
  21. 2026-08-13 02:04 UTCVendor advisory
  22. 2026-08-13 02:04 UTCGHSA enrichment
  23. 2026-08-12 15:01 UTCEG score recompute
  24. 2026-08-12 15:01 UTCVendor advisory
  25. 2026-08-12 15:01 UTCGHSA enrichment
  26. 2026-08-12 13:51 UTCEPSS rescore
  27. 2026-08-11 15:26 UTCEG score recompute
  28. 2026-08-11 15:26 UTCVendor advisory
  29. 2026-08-11 15:25 UTCGHSA enrichment
  30. 2026-08-11 00:53 UTCEG score recompute
  31. 2026-08-11 00:53 UTCVendor advisory
  32. 2026-08-11 00:53 UTCGHSA enrichment
  33. 2026-08-11 00:00 UTCEPSS rescore
  34. 2026-08-10 11:29 UTCVendor advisory
  35. 2026-08-10 11:29 UTCGHSA enrichment
  36. 2026-08-09 23:57 UTCEG score recompute
  37. 2026-08-09 23:57 UTCVendor advisory
  38. 2026-08-09 23:57 UTCGHSA enrichment
  39. 2026-08-09 13:47 UTCEPSS rescore
  40. 2026-08-09 12:54 UTCVendor advisory
  41. 2026-08-09 12:54 UTCGHSA enrichment
  42. 2026-08-09 01:51 UTCEG score recompute
  43. 2026-08-09 01:51 UTCVendor advisory
  44. 2026-08-09 01:51 UTCGHSA enrichment
  45. 2026-08-08 16:37 UTCEPSS rescore
  46. 2026-08-08 10:31 UTCVendor advisory
  47. 2026-08-08 10:31 UTCGHSA enrichment
  48. 2026-08-07 23:28 UTCEG score recompute
  49. 2026-08-07 23:28 UTCVendor advisory
  50. 2026-08-07 23:28 UTCGHSA enrichment
  51. 2026-08-07 12:24 UTCVendor advisory
  52. 2026-08-07 12:24 UTCGHSA enrichment
  53. 2026-08-07 01:21 UTCEG score recompute
  54. 2026-08-07 01:21 UTCVendor advisory
  55. 2026-08-07 01:21 UTCGHSA enrichment
  56. 2026-08-06 13:47 UTCEPSS rescore
  57. 2026-08-06 13:38 UTCEG score recompute
  58. 2026-08-06 13:38 UTCVendor advisory
  59. 2026-08-06 13:38 UTCGHSA enrichment
  60. 2026-08-06 12:34 UTCEG score recompute
  61. 2026-08-06 12:34 UTCVendor advisory
  62. 2026-08-06 12:34 UTCGHSA enrichment
  63. 2026-08-06 08:41 UTCVendor advisory
  64. 2026-08-06 08:41 UTCGHSA enrichment
  65. 2026-08-05 21:37 UTCEG score recompute
  66. 2026-08-05 21:37 UTCVendor advisory
  67. 2026-08-05 21:37 UTCGHSA enrichment
  68. 2026-08-05 19:17 UTCEPSS rescore
  69. 2026-08-05 19:17 UTCEPSS rescore
  70. 2026-08-04 15:10 UTCEPSS rescore
  71. 2026-08-04 13:26 UTCEG score recompute
  72. 2026-08-04 13:26 UTCVendor advisory
  73. 2026-08-04 13:26 UTCGHSA enrichment
  74. 2026-08-04 12:34 UTCEG score recompute
  75. 2026-08-04 12:34 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 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 62.5% 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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