Vulnerability in cryptography (CVE-2026-69249)
Summary
Vulnerability in cryptography (CVE-2026-69249). Risk of unauthorized operations or information disclosure. Exploitable via build_chain_inner. Mitigation: upgrade to 49.0.0 or later.
Original description
The description as published by the source.
Summary
When resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack.
This work was completed by Trail of Bits as part of the Patch The Planet project in collaboration with OpenAI. The finding was identified primarily by the Codex coding agent, and manually reviewed before submission.
Details
The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates.
fn build_chain_inner(
&self,
working_cert: &VerificationCertificate<'chain, B>,
current_depth: u8,
working_cert_extensions: &Extensions<'chain>,
name_chain: NameChain<'_, 'chain>,
budget: &mut Budget,
) -> ValidationResult<'chain, Chain<'chain, B>, B> {
if let Some(nc) = working_cert_extensions.get_extension(&NAME_CONSTRAINTS_OID) {
name_chain.evaluate_constraints(&nc.value()?, budget)?;
}
// Look in the store's root set to see if the working cert is listed.
// If…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-69249 has been found in cryptography.
Attackers can target a specific entry point like build_chain_inner over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade cryptography to 49.0.0 or later.
If unsure, ask your IT team or search "cryptography CVE-2026-69249" on the vendor's site.
CVE-2026-69249 (cryptography) — CWE-400
Attack surface: build_chain_inner
Patched: 49.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in cryptography. Attackers reach the vulnerable code path via build_chain_inner.
Check the vendor advisory for the affected versions of cryptography. Attack surface: build_chain_inner.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 49.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'cryptography' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'cryptography' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
cryptographyを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade cryptography to 49.0.0ステージング環境で 49.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-69249 python-cryptography
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com