# CVE-2026-54512: jackson-databind: PolymorphicTypeValidator bypass via generic type parameters allows arbitrary class instantiation > Attackers can bypass PolymorphicTypeValidator in jackson-databind to instantiate arbitrary classes via generic type parameters, leading to remote code execution. - **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 23 Jun 2026 - **Updated:** 24 Jun 2026 - **Also known as:** CLEANSTART-2026-BN64162, CLEANSTART-2026-DP19195, CLEANSTART-2026-DQ63138, CLEANSTART-2026-GO55910, CLEANSTART-2026-HB97170, CLEANSTART-2026-HO78740, CLEANSTART-2026-HP74376, CLEANSTART-2026-KU83313, CLEANSTART-2026-SE57131, CLEANSTART-2026-VS47007, CLEANSTART-2026-XF54528, CLSA-2026-1783341288, CLSA-2026-1784562620, DEBIAN-CVE-2026-54512, ECHO-ab01-c622-5a2f, GHSA-j3rv-43j4-c7qm, MINI-22v9-pgpg-87cx, MINI-2463-qw4v-95fv, MINI-25p8-h99f-9752, MINI-28cp-26f7-ffxf, MINI-28q3-xqfr-fh8h, MINI-2cfp-jh99-qrrh, MINI-2cxw-ghq2-fcpg, MINI-2h56-fx32-4fm9, MINI-2j5g-44rm-vvmv, MINI-2q53-q95m-r3hg, MINI-2r5f-6679-x258, MINI-2v52-j93w-2j42, MINI-3hpm-774f-7394, MINI-42vg-2ch7-cp62, MINI-4823-mj8p-656r, MINI-4fxv-mx92-wm7g, MINI-4hf2-v3qp-c7qq, MINI-4q2w-7v93-9hg8, MINI-4wxp-2xph-pmf7, MINI-535h-q3gg-h2rj, MINI-53x5-c9xr-pvjj, MINI-54qr-wf7c-qg2r, MINI-55cr-g7ch-5f72, MINI-5743-x993-rx4g, MINI-5c5x-gh5p-jm5v, MINI-5cvw-86ph-mp3x, MINI-5hh8-m5j9-gq54, MINI-5mrq-56r6-vpw8, MINI-5pfp-vp8g-fx78, MINI-5r4q-c46g-6c7f, MINI-5wqx-mcj9-9h45, MINI-655j-xmj9-f9f6, MINI-68cp-34vc-89xc, MINI-6frf-v35m-w8qv, MINI-6hhw-ww2x-gh6w, MINI-6hr4-jcxc-ccv5, MINI-6m6r-mxq4-2rxw, MINI-6rc8-66xg-f8m5, MINI-6rvh-2rwq-67f9, MINI-6wmr-j565-6r35, MINI-72cf-5394-f2r6, MINI-764m-4ffc-cf8j, MINI-76f7-r3h3-569x, MINI-7729-qhhf-8828, MINI-794j-8fxp-2grg, MINI-7hcv-6f2r-qpj3, MINI-7j74-492q-27q7, MINI-7jmq-r94h-2886, MINI-7m5m-4j5w-pg84, MINI-7prj-cw5q-pg84, MINI-7r7h-f8v2-vpcq, MINI-7r8g-6vf3-hqj9, MINI-7x5g-427p-2cxg, MINI-858q-ff8h-v893, MINI-85rj-w752-vm9x, MINI-85xw-jcq4-wg93, MINI-87hh-q9j7-5465, MINI-8hvh-p95j-hwmr, MINI-8p3h-7474-xxjw, MINI-8vx4-vvmc-7fq3, MINI-8w57-38c2-748p, MINI-8xq8-j22g-3vfm, MINI-9268-6fhx-gmj3, MINI-953g-g9h7-8587, MINI-99wp-j478-r9g4, MINI-9frc-f8m7-p45r, MINI-9p8m-23x5-g2cw, MINI-9rwc-jfgv-m8wr, MINI-c3hw-m59p-rj8v, MINI-c49g-5wq8-vc9x, MINI-c555-574p-grpj, MINI-c5qf-qp34-47j5, MINI-cc9r-6r7c-9p93, MINI-cf9q-gf52-hwxm, MINI-f292-rv64-c2c5, MINI-f3mv-72jq-r432, MINI-f96q-8g46-xx28, MINI-f9m9-xjx5-h7xv, MINI-fgmm-4rv5-g4h3, MINI-fr87-xmwq-9588, MINI-frmc-mhp2-9m85, MINI-fx2f-rgmw-gg4p, MINI-g38g-6rgp-gxmc, MINI-g44r-rpw2-34qp, MINI-g4jg-c87m-52qr, MINI-g5q7-2x4f-8p63, MINI-g5r7-6w29-m8jg, MINI-g66c-m6fj-x4qh, MINI-gwqr-46f7-5295, MINI-h2jw-r9qx-5w7x, MINI-h6mg-hh76-2qc3, MINI-h84c-388m-pc42, MINI-h95r-rvfp-38c6, MINI-hpjv-85m6-2fj4, MINI-hqcj-cf22-xfhj, MINI-hqh7-q6hc-rp46, MINI-hqmw-5f64-m9rq, MINI-hrh3-5m37-6c9w, MINI-hxgm-gh64-g53w, MINI-j2x7-xgwf-2vq5, MINI-j47v-f2p5-xr65, MINI-j4cg-pjj8-mw5q, MINI-j7q3-rq7h-m4xv, MINI-jmv5-m6h7-w22f, MINI-jpwx-7jfq-jf93, MINI-m398-gx96-j398, MINI-mcmp-63r3-73c4, MINI-mmjh-rp9c-7g4m, MINI-mmv2-38xg-6v33, MINI-mq7r-9m9x-9qqj, MINI-mrxx-95c8-5cvj, MINI-mx2g-77c9-2ppx, MINI-mxpx-22x3-r48x, MINI-p59w-wx7m-5f4h, MINI-p5xc-mw5f-8fjm, MINI-p7qr-fh4r-jw5v, MINI-pcq6-rcx8-567j, MINI-pghv-h4vg-9rr4, MINI-pxjp-45fh-2j76, MINI-q255-42rq-wvgc, MINI-q4mw-2759-vwwf, MINI-q7h4-287v-59rx, MINI-q7wg-27ch-w786, MINI-qc25-x8m8-m36v, MINI-qcp5-32c7-prcg, MINI-qfm6-xxjv-p7qw, MINI-qh25-w5mg-7xcw, MINI-qpmh-5xm4-9rpp, MINI-qqff-gh8c-gpcg, MINI-qrv4-2chf-4cqm, MINI-qxcw-cr72-7hqg, MINI-qxmg-8p34-p9wr, MINI-r24f-fggx-hmcx, MINI-rc6f-8vg2-9j97, MINI-rcjr-2fcv-hpv4, MINI-rh2r-25rc-vv7v, MINI-rh6v-h489-vvfq, MINI-rhcj-qqjc-qhg4, MINI-rjvj-g8p7-px5g, MINI-rp9g-gxpg-267f, MINI-v5cw-prqg-3x82, MINI-v73j-p4vp-5wxc, MINI-v7p5-3w4c-g43h, MINI-v8xm-hvqc-9cp9, MINI-v9mw-38qf-f546, MINI-vpf9-5c2j-gj9m, MINI-vwrw-h25f-fh9q, MINI-w59m-q746-x3c2, MINI-w5cg-hjgm-gpj4, MINI-w766-7qpm-phpw, MINI-w92v-5vrw-mhc9, MINI-w9q6-vv6c-4cgq, MINI-w9x4-452f-pjhm, MINI-wc8p-crvj-jmpv, MINI-wh73-chq3-x85g, MINI-wm65-7h64-8r85, MINI-wm7w-7xp2-hpxg, MINI-wpmw-vhr6-pg82, MINI-wq49-jx89-j4r7, MINI-wrg2-v27q-v82f, MINI-wrgh-rgp4-6vhx, MINI-wvw4-mmg2-jmxq, MINI-xfhh-2pj8-22mp, MINI-xhh3-9r2f-xvp7, MINI-xj8f-jjw9-7h7x, MINI-xjjx-748m-cvv3, MINI-xr42-3898-g89h, MINI-xv7v-53mj-2x37, MINI-xwgg-cq87-w8pj, MINI-xwq3-873f-6rv7, MINI-xww2-m43h-5r3x, ROOT-APP-MAVEN-CVE-2026-54512, UBUNTU-CVE-2026-54512, openSUSE-SU-2026:11132-1 ## What is CVE-2026-54512? CVE-2026-54512 is a high-severity unsafe deserialization vulnerability in Fasterxml Jackson-Databind, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.10.0 until 2.18.8, 2.21.4, and 3.1.4, jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext._resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV. If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization. An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list. This vulnerability is fixed in 2.18.8, 2.21.4, and 3.1.4. Weakness: CWE-502 (Deserialization of Untrusted Data), CWE-184 (Incomplete List of Disallowed Inputs) ## Which versions are affected by CVE-2026-54512? 8 open source packages ship an affected version, including com.fasterxml.jackson.core:jackson-databind and tools.jackson.core:jackson-databind. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `com.fasterxml.jackson.core:jackson-databind` | Maven | From 2.10.0 | 2.18.8 | | `com.fasterxml.jackson.core:jackson-databind` | Maven | From 2.10.0 | 2.18.8 | | `com.fasterxml.jackson.core:jackson-databind` | Maven | From 2.19.0 | 2.21.4 | | `com.fasterxml.jackson.core:jackson-databind` | Maven | From 2.19.0 | 2.21.4 | | `com.fasterxml.jackson.core:jackson-databind` | Maven | From 3.0.0 | 3.1.4 | | `com.fasterxml.jackson.core:jackson-databind` | Maven | From 3.0.0 | 3.1.4 | | `tools.jackson.core:jackson-databind` | Maven | From 3.0.0 | 3.1.4 | | `tools.jackson.core:jackson-databind` | Maven | From 3.0.0 | 3.1.4 | | `jackson-databind` | openSUSE:Tumbleweed | All versions | 2.18.8-2.1 | Products: Fasterxml Jackson-Databind. ## How do I fix CVE-2026-54512? Upgrade com.fasterxml.jackson.core:jackson-databind to a fixed version for your release line: 2.18.8, 2.21.4 or 3.1.4. ## Is CVE-2026-54512 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54512 exists. Public exploit code: - https://github.com/avergnaud/flight-sql-jdbc-driver-cve-2026-54512 (github_poc): https://github.com/avergnaud/flight-sql-jdbc-driver-cve-2026-54512 - Unofficial Apache Doris Spark connector 26.1.0 security fork for Java / Spark 3.5.1 / Scala 2.12; patched shaded Jackson for CVE-2026-54512. (github_poc): https://github.com/cklinisme/doris-spark-connector-cve ## Other vulnerabilities in Fasterxml Jackson-Databind - [CVE-2018-11307](https://insights.sbomify.com/CVE-2018-11307/): Deserialization of Untrusted Data in jackson-databind (critical 9.8) - [CVE-2026-54513](https://insights.sbomify.com/CVE-2026-54513/): jackson-databind: Array subtype allowlist bypass in BasicPolymorphicTypeValidator (allowIfSubTypeIsArray) (high 8.1) - [CVE-2020-14060](https://insights.sbomify.com/CVE-2020-14060/): Deserialization of untrusted data in Jackson Databind (high 8.1) - [CVE-2021-46877](https://insights.sbomify.com/CVE-2021-46877/): jackson-databind possible Denial of Service if using JDK serialization to serialize JsonNode (high 7.5) - [CVE-2019-14893](https://insights.sbomify.com/CVE-2019-14893/): Polymorphic deserialization of malicious object in jackson-databind (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-54512 and fix it if it is affected. What it is: CVE-2026-54512 is a high-severity unsafe deserialization vulnerability in Fasterxml Jackson-Databind, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54512 exists. Affected packages and fixed versions: - com.fasterxml.jackson.core:jackson-databind (Maven): affected from 2.10.0; fixed in 2.18.8 - com.fasterxml.jackson.core:jackson-databind (Maven): affected from 2.10.0; fixed in 2.18.8 - com.fasterxml.jackson.core:jackson-databind (Maven): affected from 2.19.0; fixed in 2.21.4 - com.fasterxml.jackson.core:jackson-databind (Maven): affected from 2.19.0; fixed in 2.21.4 - com.fasterxml.jackson.core:jackson-databind (Maven): affected from 3.0.0; fixed in 3.1.4 - com.fasterxml.jackson.core:jackson-databind (Maven): affected from 3.0.0; fixed in 3.1.4 - tools.jackson.core:jackson-databind (Maven): affected from 3.0.0; fixed in 3.1.4 - tools.jackson.core:jackson-databind (Maven): affected from 3.0.0; fixed in 3.1.4 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-2026-54512/ (Markdown: https://insights.sbomify.com/CVE-2026-54512/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54512 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54512 - OSV: https://osv.dev/vulnerability/CVE-2026-54512 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-54512/ Summaries are generated and may contain mistakes; the official description above is the record.