Bug 2484916 (CVE-2026-11774)

Summary: CVE-2026-11774 389-ds-base: 389-ds-base: integer overflow in SASL packet length bypasses size limit leading to heap buffer overflow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: aadhikar, bsmejkal, jachapma, mreynolds, progier, rhel-process-autobot, snegrini, spichugi, tbordaz, vashirov, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
An integer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), adding sizeof(uint32_t) to a crafted SASL packet length prefix of 0xFFFFFFFC causes unsigned wraparound to zero, bypassing the nsslapd-maxsasliosize limit and leading to a heap buffer overflow of up to approximately 2 megabytes of attacker-controlled data. After a successful SASL bind with integrity protection (SSF > 0), a remote attacker can cause a Denial of Service (DoS) or achieve Remote Code Execution (RCE). In FreeIPA and Red Hat Identity Management deployments, any domain user with a valid Kerberos ticket, enrolled host, or service account can trigger this vulnerability over the network. This flaw is independent of CVE-2025-14905, which patched schema.c only and did not modify sasl_io.c.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2492927    
Bug Blocks:    

Description OSIDB Bzimport 2026-06-04 21:00:45 UTC 
An integer overflow in the 389 Directory Server SASL I/O layer allows any SASL-authenticated user to bypass the nsslapd-maxsasliosize packet size limit and crash the LDAP server, with potential code execution on older platforms (RCE demonstrated on RHEL 8 via tcache poisoning).

After authenticating with Kerberos or DIGEST-MD5, an attacker sends a SASL-framed packet with a crafted 4-byte length prefix of 0xFFFFFFFC. In sasl_io_start_packet() (sasl_io.c:372-374), packet_length += sizeof(uint32_t) wraps to 0, bypassing the size limit check. sasl_io_read_packet() then computes bytes_remaining underflow, and NSPR passes a near-maximum recv() size into a 1024-byte encrypted_buffer — a controlled heap buffer overflow of up to maxbersize (~2MB).

In FreeIPA/IdM deployments, any domain user with a Kerberos ticket, enrolled host, or service account can trigger this remotely.

Introduced when the SASL I/O layer was first added to 389-ds-base. Independent of Finding 008 (different code path in same file). CVE-2025-14905 fix patched schema.c only; sasl_io.c untouched.

DoS confirmed on Fedora 42 (GDB-verified) and RHEL 8 production binary. RCE demonstrated on RHEL 8 (glibc 2.28) via tcache poisoning; blocked on glibc 2.32+ by safe linking.
Comment 1 errata-xmlrpc 2026-07-07 11:57:38 UTC 
This issue has been addressed in the following products:

  Red Hat Directory Server 11.9 for RHEL 8

Via RHSA-2026:36200 https://access.redhat.com/errata/RHSA-2026:36200
Comment 2 errata-xmlrpc 2026-07-07 12:20:44 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:36197 https://access.redhat.com/errata/RHSA-2026:36197
Comment 3 errata-xmlrpc 2026-07-07 12:23:16 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:36198 https://access.redhat.com/errata/RHSA-2026:36198
Comment 4 errata-xmlrpc 2026-07-07 12:27:10 UTC 
This issue has been addressed in the following products:

  Red Hat Directory Server 11.5 E4S for RHEL 8

Via RHSA-2026:36204 https://access.redhat.com/errata/RHSA-2026:36204
Comment 5 errata-xmlrpc 2026-07-07 12:30:18 UTC 
This issue has been addressed in the following products:

  Red Hat Directory Server 11.7 E4S for RHEL 8

Via RHSA-2026:36208 https://access.redhat.com/errata/RHSA-2026:36208
Comment 6 errata-xmlrpc 2026-07-07 12:30:29 UTC 
This issue has been addressed in the following products:

  Red Hat Directory Server 12.4 E4S for RHEL 9

Via RHSA-2026:36209 https://access.redhat.com/errata/RHSA-2026:36209
Comment 7 errata-xmlrpc 2026-07-07 12:40:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:36195 https://access.redhat.com/errata/RHSA-2026:36195
Comment 8 errata-xmlrpc 2026-07-07 12:46:25 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:36196 https://access.redhat.com/errata/RHSA-2026:36196
Comment 9 errata-xmlrpc 2026-07-07 13:01:51 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:36206 https://access.redhat.com/errata/RHSA-2026:36206
Comment 10 errata-xmlrpc 2026-07-07 13:02:00 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

Via RHSA-2026:36205 https://access.redhat.com/errata/RHSA-2026:36205
Comment 11 errata-xmlrpc 2026-07-07 13:21:47 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

Via RHSA-2026:36202 https://access.redhat.com/errata/RHSA-2026:36202
Comment 12 errata-xmlrpc 2026-07-07 13:25:35 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:36201 https://access.redhat.com/errata/RHSA-2026:36201
Comment 13 errata-xmlrpc 2026-07-08 06:26:58 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

Via RHSA-2026:36585 https://access.redhat.com/errata/RHSA-2026:36585
Comment 14 errata-xmlrpc 2026-07-08 09:24:19 UTC 
This issue has been addressed in the following products:

  Red Hat Directory Server 12.2 E4S for RHEL 9

Via RHSA-2026:36641 https://access.redhat.com/errata/RHSA-2026:36641
Comment 15 errata-xmlrpc 2026-07-08 11:28:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

Via RHSA-2026:36670 https://access.redhat.com/errata/RHSA-2026:36670
Comment 16 errata-xmlrpc 2026-07-08 12:11:17 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

Via RHSA-2026:36671 https://access.redhat.com/errata/RHSA-2026:36671