CVE-2026-18355389-ds-base: 389-ds-base: heap buffer overflow via sasl wrapped-record length lower-bound underflow in sasl_io_start_packet()
Updated under an hour ago ()
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It affects Red Hat Directory Server 11.5 E4S for RHEL 8 and 9 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), the wrapped-record length read from the wire is validated only against an upper bound. A small wire length (0, 1, or 2) produces an encrypted_buffer_count below the already-consumed encrypted_buffer_offset, causing an unsigned subtraction underflow in sasl_io_read_packet(). PR_Recv is then requested to read approximately 4 GiB into a 1024-byte heap buffer, resulting in a heap buffer overflow with attacker-controlled content. After a successful SASL bind with integrity protection (SSF > 0), a remote authenticated attacker can cause a denial of service or potentially achieve remote code execution. This flaw is distinct from CVE-2026-11774, whose fix only guards against upper-bound overflow.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-191
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Red Hat Red Hat Directory Server 11.5 E4S for RHEL 8 redhat:directory_server_e4s | from 8060020260908152739.0ca98e7e not affected | CNA record |
Red Hat Red Hat Directory Server 11.9 for RHEL 8 redhat:directory_server | from 8100020260904171440.37ed7c03 not affected | CNA record |
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux | from 0:3.2.0-10.el10_2 not affected | CNA record |
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support redhat:enterprise_linux_eus | from 0:3.0.6-21.el10_0 not affected | CNA record |
from 0:1.3.11.1-15.el7_9 not affected | CNA record | |
from 8040020260901171549.96015a92 not affected | CNA record | |
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support redhat:rhel_eus_long_life | from 8040020260901171549.96015a92 not affected | CNA record |
from 8080020260831180218.6dbb3803 not affected | CNA record | |
from 8080020260831180218.6dbb3803 not affected | CNA record | |
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support redhat:rhel_eus | from 0:2.6.1-24.el9_6 not affected | CNA record |
References
- https://access.redhat.com/errata/RHSA-2026:64771vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64776vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64778vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64779vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64780vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64781vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64783vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64784vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64785vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64789vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64790vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64791vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64792vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64793vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:64804vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:65119vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:79217vendor-advisory, x-refsource-redhat
- https://access.redhat.com/security/cve/CVE-2026-18355vdb-entry, x-refsource-redhat
- https://bugzilla.redhat.com/show_bug.cgi?id=2509186issue-tracking, x-refsource-redhat
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.