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CVE-2026-43823

HIGH 7.5 PoC AVAILABLE

Published 2026-07-23 · Last modified 2026-07-23

When initializing an RSA public key from DER or PEM bytes throws an error, the EVP_PKEY* is double-freed: first in the catch block, then in the deinit. This can lead to a crash on future memory allocations. This double-free manifests when BoringSSL cannot decode the public key from the bytes provided. This vulnerability is addressed in swift-crypto version 4.5.1.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 17th percentile

○ In CISA KEV ● Public exploit / PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-43823/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-43823/poc.json

Affected

Vendors Apple

Products Swift Crypto

Weakness (CWE)

  • CWE-415: Double Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

All CVSS metrics

  • HIGH 7.5 v3.1 · ADP Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
  • HIGH 7.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Exploits & PoC

Sources: NVD · CVE.org · EPSS