{"id":"CVE-2026-89539","title":"SUNRPC: reject duplicate CREDS_VALUE options","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: reject duplicate CREDS_VALUE options\n\ngssx_dec_option_array() walks the wire-supplied option array and, for\nevery entry whose name matches CREDS_VALUE, calls\ngs…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-772"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 4b5ebb4f91a6152a0f7b1253f701197e5710d4da","Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < f615b884310bf82d0014e3b5a92eb9aa88146685","Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 7a1d0501cbb962beba23377035d667bf3c1726ee","Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 9d94f046b23de0f77849ea69133063c949297e30","Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 2e4ce62385c1b8a887c5370af058ac7b52a8eaf9","Linux 3.10"],"published":"2026-09-11","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:47:46.957Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89539","references":[{"url":"https://git.kernel.org/stable/c/4b5ebb4f91a6152a0f7b1253f701197e5710d4da"},{"url":"https://git.kernel.org/stable/c/f615b884310bf82d0014e3b5a92eb9aa88146685"},{"url":"https://git.kernel.org/stable/c/7a1d0501cbb962beba23377035d667bf3c1726ee"},{"url":"https://git.kernel.org/stable/c/9d94f046b23de0f77849ea69133063c949297e30"},{"url":"https://git.kernel.org/stable/c/2e4ce62385c1b8a887c5370af058ac7b52a8eaf9"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89539.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89539"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532304"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89539"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89539"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00168,"epssPercentile":0.06161,"ingestedAt":"2026-09-14T11:11:19.886Z","slug":"CVE-2026-89539","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: reject duplicate CREDS_VALUE options\n\ngssx_dec_option_array() walks the wire-supplied option array and, for\nevery entry whose name matches CREDS_VALUE, calls\ngssx_dec_linux_creds() on the same struct svc_cred. That helper\nunconditionally installs a fresh groups_alloc() result into\ncreds->cr_group_info without releasing whatever pointer was already\nthere:\n\n    for (i = 0; i < count; i++) {\n        ... decode name ...\n        if (length == sizeof(CREDS_VALUE) &&\n            memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {\n            err = gssx_dec_linux_creds(xdr, creds);\n            ...\n        }\n    }\n\nA reply that carries two CREDS_VALUE entries therefore overwrites\ncr_group_info on the second iteration and orphans the group_info\nallocated by the first call. The earlier free_creds path only\nreleases the last cr_group_info via free_svc_cred(), so the first\nallocation's refcount stays at one and its kvmalloc-backed storage\nis leaked. No in-tree caller of gssp_accept_sec_context_upcall()\nexpects more than one CREDS_VALUE per reply.\n\nFix by tracking whether a CREDS_VALUE option has already been\ndecoded and returning -EINVAL on any subsequent match, so the\nfree_creds path releases the single group_info that was installed.\n\n## Affected\n\n- `Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 4b5ebb4f91a6152a0f7b1253f701197e5710d4da`\n- `Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < f615b884310bf82d0014e3b5a92eb9aa88146685`\n- `Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 7a1d0501cbb962beba23377035d667bf3c1726ee`\n- `Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 9d94f046b23de0f77849ea69133063c949297e30`\n- `Linux >= 1d658336b05f8697d6445834f8867f8ad5e4f735 < 2e4ce62385c1b8a887c5370af058ac7b52a8eaf9`\n- `Linux 3.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89539.json)","depth":"sunlit","depthScore":32,"depthScoreParts":{"impact":32.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205429,"id":"CVE-2026-89539","ts":1789576710438,"field":"cvss","old":null,"new":"5.9"},{"seq":205428,"id":"CVE-2026-89539","ts":1789576710438,"field":"severity","old":"none","new":"medium"}]}