CVE Explorer
CVE-2026-59876
protobufjs compiles protobuf definitions into JavaScript (JS) functions. From 8.2.0 until 8.6.5, the protobufjs Text Format extension parsed string-keyed map entries using ordinary property assignment, allowing a map entry with key __proto__ to change the prototype of the returned map object instead of creating an own map entry in protobufjs/ext/textformat. This issue is fixed in version 8.6.5.
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"product":"protobuf.js","vendor":"protobufjs","versions":[{"status":"affected","version":">= 8.2.0, < 8.6.5"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.8,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-1321","description":"CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/problemTypes/0/descriptions/0
Source references
4 source assertions{"name":"https://github.com/protobufjs/protobuf.js/commit/9f97fe413072d3beb52c74e62d88ea8adc9444d8","tags":["x_refsource_MISC"],"url":"https://github.com/protobufjs/protobuf.js/commit/9f97fe413072d3beb52c74e62d88ea8adc9444d8"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/references/2
{"name":"https://github.com/protobufjs/protobuf.js/pull/2335","tags":["x_refsource_MISC"],"url":"https://github.com/protobufjs/protobuf.js/pull/2335"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/references/1
{"name":"https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.6.5","tags":["x_refsource_MISC"],"url":"https://github.com/protobufjs/protobuf.js/releases/tag/protobufjs-v8.6.5"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/references/3
{"name":"https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-jfj6-75fj-8934","tags":["x_refsource_CONFIRM"],"url":"https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-jfj6-75fj-8934"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:9ad4637fe71c14b16c61ed0ba240ba69281a8293189bde5d05a13e1376688db5 · sha256:66719d9f32d075da… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.