Linux Kernel up to 6.6.156/6.12.108/6.18.49/7.2.3 SUNRPC svcauth_gss_decode_credbody use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.11

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.6.156/6.12.108/6.18.49/7.2.3. Impacted is the function svcauth_gss_decode_credbody of the component SUNRPC. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2026-93207. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.6.156/6.12.108/6.18.49/7.2.3 and classified as very critical. This vulnerability affects the function svcauth_gss_decode_credbody of the component SUNRPC. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry svcauth_gss_decode_credbody() writes the caller's rpc_gss_wire_cred field by field and assigns gc_ctx.len only on the success tail. The caller storage is svcdata->clcred, which lives in the per-svc_rqst gss_svc_data and is reused across requests. Early decode failures leave partially decoded state mixed with residue from the prior request. The trailing body_len tightness check is the sharpest case: xdr_stream_decode_opaque_inline() has already written gc_ctx.data with a borrowed inline pointer into the current request's XDR pages, but gc_ctx.len retains its prior value. Once the request pages are released the pooled clcred carries a dangling pointer paired with a stale length. Zero the caller's rpc_gss_wire_cred at function entry so that every early-return path leaves a deterministic all-zero cred. On the trailing tightness-check path, gc_ctx.len is now zero instead of stale, which neuters length-driven consumers such as gss_svc_searchbyctx() that would otherwise walk the dangling data pointer.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-93207 since 09/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/24/2026).

Upgrading to version 6.6.157, 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch 56b29d62017c7dd1718d060dd5b3a2ce61095d0c/0e18641708eaa8bc3c1ff338cd844aeadbd52bac/e0778464049b0238f2915a40007a4154f86cf351/0fa8a8acae57e6373962741d5b06d13f44aba6a9/11539e8fcce0b0af062ae5fecf7b3676c2f7aeed is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.157/6.12.109/6.18.50/7.2.4/7.3-rc1
Patch: 56b29d62017c7dd1718d060dd5b3a2ce61095d0c/0e18641708eaa8bc3c1ff338cd844aeadbd52bac/e0778464049b0238f2915a40007a4154f86cf351/0fa8a8acae57e6373962741d5b06d13f44aba6a9/11539e8fcce0b0af062ae5fecf7b3676c2f7aeed

Timelineinfo

09/17/2026 CVE reserved
09/24/2026 +7 days Advisory disclosed
09/24/2026 +0 days VulDB entry created
09/24/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-93207 (🔒)
GCVE (CVE): GCVE-0-2026-93207
GCVE (VulDB): GCVE-100-409414

Entryinfo

Created: 09/24/2026 17:44
Changes: 09/24/2026 17:44 (59)
Complete: 🔍
Cache ID: 216::103

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