# CVE-2026-116585: Go JOSE: Panic during CBC-HMAC processing - **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Fix available:** Yes - **Published:** 26 Oct 2026 - **Updated:** 26 Oct 2026 - **Also known as:** GHSA-4w3g-jfj2-cw2q, MINI-22gq-jqh7-rg24, MINI-2fhf-jg85-23q3, MINI-2gwq-7cx7-99r7, MINI-2p59-v5vw-74gx, MINI-2vj7-hg8g-cc82, MINI-2vv6-mh6q-rppx, MINI-3mg6-pf38-m5p5, MINI-4565-7mcr-r5fm, MINI-4p8m-4726-xp3c, MINI-5h2c-9f4g-gqr2, MINI-6g87-4rjc-3cx2, MINI-6qp5-vxx4-973f, MINI-6r54-57v3-m4r4, MINI-6w77-2xpc-mxr4, MINI-74jq-mvhv-fj8g, MINI-7hx9-gqgr-fjg7, MINI-7pm4-8x6m-5vhw, MINI-8cxw-x8rr-2w9v, MINI-8h3g-m586-rfjr, MINI-99ch-v8fj-7c2f, MINI-9x9f-x8c3-qgq9, MINI-cgjr-vpgr-w5qg, MINI-cw4j-vvp6-mmfh, MINI-f63g-hpx5-23cg, MINI-fc2v-mp7m-rw27, MINI-fm9x-8p88-p4wx, MINI-frhm-9qhm-mm97, MINI-g4jf-q664-f9ch, MINI-gchr-82x5-g9qv, MINI-gf5p-fwfc-wp66, MINI-j25q-4c8w-r8hq, MINI-j36p-f5r3-x8hp, MINI-j9j2-q4qq-vm97, MINI-j9j4-mq7j-pwhr, MINI-jgq6-428w-h3fj, MINI-jvv2-7p48-vw5x, MINI-m35h-x3p3-rvr5, MINI-p5rf-c5mw-46m4, MINI-p8ph-5939-c5w8, MINI-q593-7rgf-h9x9, MINI-q6vq-chqv-85ph, MINI-v3w8-82g7-r5p7, MINI-v43f-2x3c-jprv, MINI-v7f9-rvxx-mh9p, MINI-v9mf-cwpm-c42c, MINI-w32c-qgph-2x5j, MINI-wh67-855m-gxhp, MINI-wpvh-xv72-82m4, MINI-wr65-h9v8-jmc3, MINI-x45j-w6x4-8f79, MINI-x75w-phwj-3fx5, MINI-xc95-8gxr-2j7c, MINI-xj85-m9wj-3835, MINI-xmm7-w8m9-6vh8, MINI-xpf5-3pxc-h7rm, UBUNTU-CVE-2026-116585 ## What is CVE-2026-116585? CVE-2026-116585 is a medium-severity vulnerability in go-jose, published on 26 Oct 2026. ### Official description Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.5, decrypting untrusted JWE ciphertext with A128CBC-HS256, A192CBC-HS384, or A256CBC-HS512 can pass an empty ciphertext buffer to CBC-HMAC unpadding. Insufficient validation allows the empty buffer to be indexed, causing a panic and denial of service. Applications that decrypt attacker-controlled ciphertext with one of these content-encryption algorithms are affected. This issue is fixed in version 4.1.5. Weakness: CWE-129 (Improper Validation of Array Index) ## Which versions are affected by CVE-2026-116585? 4 open source packages ship an affected version, including github.com/go-jose/go-jose/v3 and github.com/go-jose/go-jose/v4. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/go-jose/go-jose/v3` | Go | All versions to 3.0.5 | None | | `github.com/go-jose/go-jose/v3` | Go | All versions to 3.0.5 | None | | `github.com/go-jose/go-jose/v4` | Go | All versions | 4.1.5 | | `github.com/go-jose/go-jose/v4` | Go | All versions | 4.1.5 | ## How do I fix CVE-2026-116585? Upgrade to a fixed version. ## Is CVE-2026-116585 being exploited? There is no known exploitation of CVE-2026-116585 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-116585 and fix it if it is affected. What it is: CVE-2026-116585 is a medium-severity vulnerability in go-jose, published on 26 Oct 2026. Exploitation: There is no known exploitation of CVE-2026-116585 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/go-jose/go-jose/v3 (Go): affected all versions up to 3.0.5; no fix listed - github.com/go-jose/go-jose/v3 (Go): affected all versions up to 3.0.5; no fix listed - github.com/go-jose/go-jose/v4 (Go): affected all versions; fixed in 4.1.5 - github.com/go-jose/go-jose/v4 (Go): affected all versions; fixed in 4.1.5 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-116585/ (Markdown: https://insights.sbomify.com/CVE-2026-116585/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116585 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116585 - OSV: https://osv.dev/vulnerability/CVE-2026-116585 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-116585/ Summaries are generated and may contain mistakes; the official description above is the record.