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CVE-2026-11850

Krb5: krb5: integer underflow in berval2tl_data() leads to heap out-of-bounds read

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.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerRed Hat
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Produkt Red Hat Hardened Images
Default Statusaffected
Version 1.22.2-8.hum1
Version < *
Status unaffected
HerstellerRed Hat
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Produkt Red Hat Enterprise Linux 10
Default Statusaffected
HerstellerRed Hat
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Produkt Red Hat Enterprise Linux 6
Default Statusaffected
HerstellerRed Hat
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Produkt Red Hat Enterprise Linux 7
Default Statusaffected
HerstellerRed Hat
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Produkt Red Hat Enterprise Linux 8
Default Statusaffected
HerstellerRed Hat
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Produkt Red Hat Enterprise Linux 9
Default Statusaffected
HerstellerRed Hat
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Produkt Red Hat OpenShift Container Platform 4
Default Statusaffected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.26% 0.172
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
secalert@redhat.com 5 0.7 4.2
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H
CWE-191 Integer Underflow (Wrap or Wraparound)

The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

https://access.redhat.com/security/cve/CVE-2026-11850
https://bugzilla.redhat.com/show_bug.cgi?id=2459970
https://access.redhat.com/errata/RHSA-2026:25520