{"id":"CVE-2026-119148","kind":"vulnerability","aliases":["CVE-2026-119148"],"related":[],"title":"Incomplete string validation in AWS aws-nitro-enclaves-sdk-c before 0.4.6 may allow a third party to impersonate the…","description":"CVE-2026-119116 and CVE-2026-119148 - Issues in AWS Nitro Enclaves SDK for C\n\n### CVE-2026-119116 and CVE-2026-119148 - Issues in AWS Nitro Enclaves SDK for C\n\nBulletin ID: 2026-157-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/30/2026 09:00 AM PDT\n\nDescription:\n\nThe AWS Nitro Enclaves SDK for C (aws-nitro-enclaves-sdk-c) is a library and set of example tools, including kmstool-enclave, for building applications that run inside AWS Nitro Enclaves and call AWS KMS using cryptographic attestation.\n\nWe identified CVE-2026-119116, a use-after-free in the SetClient command handler of the kmstool-enclave example application, where an application that executes on the parent EC2 instance could send crafted messages over vsock to corrupt heap memory inside the enclave and execute arbitrary code within it. Only enclave images that include kmstool-enclave, or code derived from it, are affected.\n\nWe also identified CVE-2026-119148, an input validation issue in the SDK library where the AWS KMS server name is built from a caller-supplied region string. A third party could supply a crafted region to impersonate KMS to the enclave and inject forged responses, such as actor-chosen key material.\n\nImpacted versions: aws-nitro-enclaves-sdk-c <= v0.4.5 (CVE-2026-119116 affects kmstool-enclave only; CVE-2026-119148 affects the library)\n\nResolution:\n\nBoth issues have been addressed in aws-nitro-enclaves-sdk-c version v0.4.6. Customers who build enclave images which consume the aws-nitro-enclaves-sdk-c library should upgrade it to v0.4.6 and rebuild their enclave images.\n\nWorkarounds:\n\nThere are no workarounds. Upgrading is required.\n\nReferences:\n\n- CVE-2026-119116\n- CVE-2026-119148\n- GHSA-f6f6-6f88-r57j\n- GHSA-cfhm-qfw4-j7qq\n\nAcknowledgement:\n\nWe would like to thank Trail of Bits for reporting CVE-2026-119116 and collaborating on this issue through the coordinated vulnerability disclosure process.\n\n Please email aws-security@amazon.com with any security questions or concerns.","summary":"The AWS Nitro Enclaves SDK for C has two issues: a use-after-free in the kmstool-enclave example's SetClient handler that lets a process on the parent EC2 instance run code inside the enclave, and a KMS server name built from a caller-supplied region that lets a third party impersonate KMS and inject forged responses such as attacker-chosen key material. Both are fixed in v0.4.6.","severity":"high","cvss":8.2,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["aws","c","infrastructure","kms","lab-disclosure","nitro-enclaves","self-hosted"],"not_affected_if":["no-kmstool-enclave","no-nitro-enclaves"],"how_to_check":"- Check the aws-nitro-enclaves-sdk-c version your enclave images build against; versions `<= v0.4.5` are affected.\n- Check whether your enclave images include kmstool-enclave or code derived from it; only those are affected by CVE-2026-119116.","fix":"- aws-nitro-enclaves-sdk-c: upgrade to `v0.4.6` and rebuild enclave images that consume the library.","status":"open","published_at":"2026-10-30T00:00:00+00:00","first_seen_at":"2026-10-30T16:50:06+00:00","triaged_at":"2026-10-30T16:50:30+00:00","updated_at":"2026-10-30T17:31:39+00:00","category":"infrastructure","confidence":0.7,"triage":{"at":"2026-10-30T16:50:30Z","model":"claude-haiku-5-5","output":{"fix":"- aws-nitro-enclaves-sdk-c: upgrade to `v0.4.6` and rebuild enclave images that consume the library.","reach":"local","title":"AWS Nitro Enclaves SDK for C: memory corruption and KMS impersonation flaws","impact":"high","summary":"The AWS Nitro Enclaves SDK for C has two issues: a use-after-free in the kmstool-enclave example's SetClient handler that lets a process on the parent EC2 instance run code inside the enclave, and a KMS server name built from a caller-supplied region that lets a third party impersonate KMS and inject forged responses such as attacker-chosen key material. Both are fixed in v0.4.6.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["aws","nitro-enclaves","kms","c","self-hosted"],"confidence":0.7,"fix_status":"available","needs_auth":"unknown","worst_case":"code runs inside the enclave; forged KMS responses supply attacker-chosen keys","analyst_note":"","how_to_check":"- Check the aws-nitro-enclaves-sdk-c version your enclave images build against; versions `<= v0.4.5` are affected.\n- Check whether your enclave images include kmstool-enclave or code derived from it; only those are affected by CVE-2026-119116.","plain_action":"","needs_analyst":false,"not_affected_if":["no-nitro-enclaves","no-kmstool-enclave"],"who_is_affected":"Teams that build applications running inside AWS Nitro Enclaves using the aws-nitro-enclaves-sdk-c library, and calling KMS from the enclave. Enclave images without the library, or without kmstool-enclave for the first issue, are not affected by that issue.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000815,"input_tokens":4898,"output_tokens":650,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-119116':115C,130C,208C,335C,398C,425C '-119148':23A,26A,119C,134C,275C,343C,401C '-157':146C '-2026':22A,25A,114C,118C,129C,133C,207C,274C,334C,342C,397C,400C,424C '0.4.6':13A '00':159C '09':158C '10/30/2026':157C '2026':145C '6f88':405C 'acknowledg':412C 'actor':320C 'actor-chosen':319C 'address':352C 'affect':269C,336C,344C 'allow':15A 'also':271C 'applic':190C,225C,228C 'arbitrari':251C 'attack':104B 'attacker-chosen':103B 'attent':154C 'attest':203C 'aw':5A,7A,27B,41B,122C,137C,147C,149C,164C,171C,194C,199C,286C,327C,355C,371C 'aws-nitro-enclaves-sdk-c':6A,170C,326C,354C,370C 'aws-security@amazon.com':439C 'bit':420C 'build':189C,364C 'built':83B,291C 'bulletin':143C 'c':11A,28B,46B,127C,142C,169C,175C,331C,359C,375C 'call':198C 'caller':87B,295C 'caller-suppli':86B,294C 'cfhm':409C 'chosen':105B,321C 'code':74B,252C,264C 'collabor':427C 'command':217C 'concern':445C 'consum':368C 'content':150C 'coordin':433C 'corrupt':243C 'could':236C,302C 'craft':238C,305C 'cryptograph':202C 'custom':362C 'cve':21A,24A,113C,117C,128C,132C,206C,273C,333C,341C,396C,399C,423C 'date':156C 'deriv':265C 'descript':162C 'disclosur':33B,435C 'ec2':71B,234C 'email':438C 'enclav':9A,36B,43B,59B,77B,124C,139C,166C,173C,187C,196C,223C,248C,256C,262C,312C,329C,339C,357C,365C,373C,385C 'exampl':60B,182C,224C 'execut':230C,250C 'f6f6':404C 'fix':110B 'forg':99B,315C 'free':54B,213C 'ghsa':403C,408C 'ghsa-cfhm-qfw4-j7qq':407C 'ghsa-f6f6-6f88-r57j':402C 'handler':63B,218C 'heap':244C 'host':39B 'id':144C 'identifi':205C,272C 'imag':257C,366C,386C 'impact':324C 'imperson':20A,95B,308C 'import':152C 'includ':184C,259C 'incomplet':1A 'infrastructur':29B 'inject':98B,314C 'input':277C 'insid':75B,193C,246C 'instanc':72B,235C 'issu':49B,120C,135C,279C,349C,430C 'j7qq':411C 'key':106B,322C 'kms':30B,80B,96B,200C,287C,309C 'kmstool':58B,186C,222C,261C,338C 'kmstool-enclav':57B,185C,221C,260C,337C 'lab':32B 'lab-disclosur':31B 'let':65B,91B 'librari':178C,283C,346C,376C 'like':415C 'materi':107B,323C 'may':14A 'memori':245C 'messag':239C 'name':82B,289C 'nitro':8A,35B,42B,123C,138C,165C,172C,195C,328C,356C,372C 'nitro-enclav':34B 'parent':70B,233C 'parti':18A,94B,301C 'pdt':161C 'pleas':437C 'process':67B,436C 'public':155C 'qfw4':410C 'question':443C 'r57j':406C 'rebuild':383C 'refer':395C 'region':89B,297C,306C 'report':422C 'requir':153C,394C 'resolut':347C 'respons':100B,316C 'run':73B,192C 'scope':148C 'sdk':10A,44B,125C,140C,167C,174C,282C,330C,358C,374C 'secur':442C 'self':38B 'self-host':37B 'send':237C 'server':81B,288C 'set':180C 'setclient':62B,216C 'string':2A,298C 'suppli':88B,296C,303C 'thank':417C 'third':17A,93B,300C 'tool':183C 'trail':418C 'two':48B 'type':151C 'upgrad':378C,392C 'use':52B,201C,211C 'use-after-fre':51B,210C 'v0.4.5':332C 'v0.4.6':112B,361C,381C 'valid':3A,278C 'version':325C,360C 'vsock':241C 'vulner':434C 'within':253C 'workaround':387C,391C 'would':414C","nicknames":[],"mitigations":[],"who_affected":"Teams that build applications running inside AWS Nitro Enclaves using the aws-nitro-enclaves-sdk-c library, and calling KMS from the enclave. Enclave images without the library, or without kmstool-enclave for the first issue, are not affected by that issue.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T00:00:00+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"ff89ba41-3aa1-4d27-914a-91399e9639e5","poc_count":0,"sources":[{"source":"lab","external_id":"https://aws.amazon.com/security/security-bulletins/rss/2026-157-aws/#CVE-2026-119148","url":"https://aws.amazon.com/security/security-bulletins/rss/2026-157-aws/","severity":null,"published_at":"2026-10-30T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-30T16:50:06+00:00","fetched_at":"2026-10-30T16:50:06+00:00","note":"AWS: CVE-2026-119116 and CVE-2026-119148 - Issues in AWS Nitro Enclaves SDK for C"},{"source":"nvd","external_id":"CVE-2026-119148","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119148","severity":null,"published_at":"2026-10-30T17:17:16+00:00","modified_at":"2026-10-30T17:17:16+00:00","first_seen_at":"2026-10-30T17:31:39+00:00","fetched_at":"2026-10-30T17:31:40+00:00","note":null}],"documents":[{"id":24698,"url":"https://aws.amazon.com/security/security-bulletins/rss/2026-157-aws/","title":"AWS: CVE-2026-119116 and CVE-2026-119148 - Issues in AWS Nitro Enclaves SDK for C","kind":"advisory","source":"lab","publisher":"research","text":"CVE-2026-119116 and CVE-2026-119148 - Issues in AWS Nitro Enclaves SDK for C\n\n### CVE-2026-119116 and CVE-2026-119148 - Issues in AWS Nitro Enclaves SDK for C\n\nBulletin ID: 2026-157-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/30/2026 09:00 AM PDT\n\nDescription:\n\nThe AWS Nitro Enclaves SDK for C (aws-nitro-enclaves-sdk-c) is a library and set of example tools, including kmstool-enclave, for building applications that run inside AWS Nitro Enclaves and call AWS KMS using cryptographic attestation.\n\nWe identified CVE-2026-119116, a use-after-free in the SetClient command handler of the kmstool-enclave example application, where an application that executes on the parent EC2 instance could send crafted messages over vsock to corrupt heap memory inside the enclave and execute arbitrary code within it. Only enclave images that include kmstool-enclave, or code derived from it, are affected.\n\nWe also identified CVE-2026-119148, an input validation issue in the SDK library where the AWS KMS server name is built from a caller-supplied region string. A third party could supply a crafted region to impersonate KMS to the enclave and inject forged responses, such as actor-chosen key material.\n\nImpacted versions: aws-nitro-enclaves-sdk-c <= v0.4.5 (CVE-2026-119116 affects kmstool-enclave only; CVE-2026-119148 affects the library)\n\nResolution:\n\nBoth issues have been addressed in aws-nitro-enclaves-sdk-c version v0.4.6. Customers who build enclave images which consume the aws-nitro-enclaves-sdk-c library should upgrade it to v0.4.6 and rebuild their enclave images.\n\nWorkarounds:\n\nThere are no workarounds. Upgrading is required.\n\nReferences:\n\n- CVE-2026-119116\n- CVE-2026-119148\n- GHSA-f6f6-6f88-r57j\n- GHSA-cfhm-qfw4-j7qq\n\nAcknowledgement:\n\nWe would like to thank Trail of Bits for reporting CVE-2026-119116 and collaborating on this issue through the coordinated vulnerability disclosure process.\n\n Please email aws-security@amazon.com with any security questions or concerns.","published_at":"2026-10-30T00:00:00+00:00","relation":"advisory","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}