GHSA-f9v2-4w9p-2cwc · 深刻度： critical — Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input...
Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input validation on the cipher and tag length fields of AuthEnvelopedData containers, leading to various potential compromises. Impact Summary: Attackers making use of these vulnerabilities may achieve key-equivalent functionality for a given CMS recipient and/or bypass integrity validation for a given message. In one use case, an attacker may send a CMS message containing AuthEnvelopedData with the cipher specified as a non-AEAD cipher. OpenSSL erroneously allows this selection, and attempts to decrypt and validate the message. An on-path attacker who captures one legitimate AES-GCM AuthEnvelopedData addressed to the victim can re-emit it with the recipientInfos set left byte-for-byte intact, so the victim's private key still unwraps the genuine CEK (the content-encryption key), but with the inner OID rewritten to AES-256-OFB (Output Feedback Mode, an unauthenticated keystream mode) and with an attacker-chosen IV and ciphertext. The victim initializes AES-256-OFB under the real CEK, never consults the MAC field, and CMS_decrypt() returns success. If the application under attack responds to the attacker with any indicator showing success or failure of the decryption effort, it is possible for the attacker to use this as an oracle to obtain key equivalent functionality for the CEK used for the chosen recipient of the message. In another use case, an attacker can reduce the tag length of the chosen AEAD cipher for a given AuthEnvelopedData container to be a single byte long, allowing an attacker to brute force CMS decryption, producing an integrity bypass for applications that trust CMS_decrypt() to reject modified content. The FIPS modules are not affected by this issue.
総合評価: CVE-2026-34182 は中リスク（40.9/100）。CVSS 深刻度は重大。悪用される可能性が高い（EPSS 0.22%、12 パーセンタイル） 推奨対応: 影響資産を整理し、修補計画に組み込んでください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.00% | 0.22% | +0.21% |
| 2 | 2026-06-10 | — | 0.00% | — |
EPSS の全履歴 （全 2 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 9.1 | 3.1 | CRITICAL |
|
3.9 | 5.2 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
GHSA-f9v2-4w9p-2cwc · 深刻度： critical — Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2026-34182 unimportant priority: Debian including 1 source packages (openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2026-34182 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-34182 |
suse
|
medium | CVE-2026-34182 severity moderate: SUSE including 43 source package names (compat-openssl098, latest:libexpat1-2.7.1-4.1, …), 317 product×package rows across 64 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (64 product lines)): Known Not Affected 236, Fixed 69, First Fixed 12. | https://www.suse.com/security/cve/CVE-2026-34182/ |
ubuntu
|
medium | CVE-2026-34182 medium priority: Ubuntu including 5 source packages (edk2, nodejs, openssl, openssl-fips, openssl1.0), 35 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): not-affected 14, DNE 8, needs-triage 8, released 4, needed 1. | https://ubuntu.com/security/CVE-2026-34182 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| openssl | openssl | >= 3.0.0, < 3.0.21 | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
| openssl | openssl | >= 3.4.0, < 3.4.6 | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
| openssl | openssl | >= 3.5.0, < 3.5.7 | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
| openssl | openssl | >= 3.6.0, < 3.6.3 | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
| openssl | openssl | 4.0.0 | cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:* |