Krb5: krb5: integer underflow in berval2tl_data() leads to heap out-of-bounds read
Priority LOW 22CWE-191Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · High
- Fix status
- Partial Red Hat: 1 fixed, 8 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
An integer underflow vulnerability was found in MIT krb5 in the berval2tl_data() function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c. The function performs an unsigned subtraction (bv_len - 2) without a prior bounds check. When bv_len is 0 or 1, the subtraction wraps to a large value which is then truncated to uint16_t, yielding 0xFFFE (65534) or 0xFFFF (65535). The subsequent malloc succeeds and memcpy reads up to 65534 bytes from a 0-1 byte buffer, resulting in a heap out-of-bounds read. The attack vector involves a malicious or compromised LDAP KDB backend returning a krbExtraData attribute with bv_len < 2, triggering the underflow when the KDC or kadmind reads principal data.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00271 19th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 8 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Hardened Images | — | 1.22.2-8.hum1 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 10 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — | No fix listed | CNA |
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in 1.22.2-8.hum1 Patch available CNA
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift AI (RHOAI) VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 5 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:hummingbird:1 | 1 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:10 | 10 | — | Red Hat |
| cpe:/o:redhat:rhel_els:6 | 6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:7 | 7 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8 | 8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9 | 9 | — | Red Hat |
| cpe:/a:redhat:openshift_ai | — | — | Red Hat |
| cpe:/a:redhat:openshift:4 | 4 | — | Red Hat |
| cpe:/a:redhat:openshift:5 | 5 | — | Red Hat |
- cpe:/a:redhat:hummingbird:1 Versions 1 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
- cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
- cpe:/a:redhat:openshift_ai Versions — — ·Red Hat
- cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
- cpe:/a:redhat:openshift:5 Versions 5 — ·Red Hat
Remediation
Red Hat 1 advisory
- RHSA-2026:25520 Released 2026-06-12 · Red Hat rating ModerateRed Hat Hardened Images RPMs Security Update
- Red Hat Hardened Images krb5-1.22.2-8.hum1@src, krb5-devel-1.22.2-8.hum1@aarch64, krb5-devel-1.22.2-8.hum1@x86_64 +16
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | — |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:25520 |
Not affected: 1 product
- Red Hat OpenShift AI (RHOAI)
Timeline
- 2026-10-02 Threatist record created from CVE-2026-11850
- 2026-10-03 Alias added: GHSA-85rq-mqr4-hjw7
- 2026-10-31 Affected versions changed · CNA
- 2026-10-31 Affected versions changed · Red Hat
- 2026-11-06 Affected versions changed · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
More Red Hat vulnerabilities
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- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-11850 · CVE Program
- CVE-2026-11850 · NVD
- FIRST EPSS
- GHSA-85rq-mqr4-hjw7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-11850 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences