CVE-2026-6477: PostgreSQL · Use of Inherently Dangerous Function
Affects PostgreSQLSource CVE Database V5
Not known to be exploited · CVSS 8.8 High · fixed in 18.4 : patch PostgreSQL soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 18.4, 17.10, 16.14 +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| PostgreSQL | Affected
| Fixed in
|
| PostgreSQL | Affected
| Fixed in
|
| PostgreSQL | Affected
| Fixed in
|
| PostgreSQL | Affected
| Fixed in
|
| PostgreSQL | Affected
| Fixed in
|
Postgresqlpostgresql/postgresqlpkg:deb/postgresql/postgresqlOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in PostgreSQL versions 18.4, 17.10, 16.14, 15.18, and 14.23 and later. Users should upgrade to these fixed versions or later. Until patched, users should avoid connecting to untrusted or potentially compromised PostgreSQL servers using psql, pg_dump, or other client tools that use the vulnerable libpq functions. The vendor advisory explicitly recommends only connecting to trusted servers as a mitigation. No other specific mitigations are noted.
Description
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.
References
- postgresql.org/support/security/CVE-2026-6477/ (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-6477 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2477442 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6477.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27718 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44391 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27743 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27742 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27738 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28999 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28208 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26181 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28143 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44420 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34362 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34363 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:47090 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29815 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:32994 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35880 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34043 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:42555 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26561 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33497 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29953 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33441 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26524 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29904 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:32983 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26525 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29212 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44308 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28037 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26203 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26204 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27741 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:21182 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22878 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:44481 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49521 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49908 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:49909 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50863 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:50779 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:54760 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:58981 (opens in a new tab)