Vulnerability in eml_parser (CVE-2026-44844)
Summary
Vulnerability in eml_parser (CVE-2026-44844). Risk of unauthorized operations or information disclosure. Exploitable via RecursionError. Mitigation: upgrade to 3.0.1 or later.
Original description
The description as published by the source.
Summary
EmlParser.get_raw_body_text() recurses unconditionally for every nested message/rfc822 attachment without any depth limit. An attacker who can supply a badly crafted EML file with approximately 120 nested message/rfc822 parts triggers an unhandled RecursionError and aborts parsing of the message. A 12 KB EML file is enough to crash a worker.
Though this causes the parser to crash, it is an unlikely scenario as the suggested EML that crashes the parser would not pass basic RFC compliance tests.
Details
The vulnerable function is EmlParser.get_raw_body_text() in eml_parser/parser.py. For every part of type multipart/*, the function iterates over its sub-parts; for every sub-part of type message/rfc822, it calls itself recursively on the inner message:
There is no depth parameter and no early-abort. CPython's default sys.recursionlimit is 1000. Each level of message/rfc822 nesting adds approximately 8 frames to the stack (parser code + stdlib _header_value_parser calls), so roughly 120 nested levels exhaust the limit.
The RecursionError is not caught anywhere along the call chain, so it propagates out of decode_email_bytes() and aborts processing of the entire message.
PoC
Environment: Python 3.12.3, eml_parser 3.0.0 (pip install eml_parser==3.0.0), default sys.recursionlimit=1000, Ubuntu 24.04 aarch64. No special configuration of EmlParser, default constructor.
Self-contained reproducer that builds the PoC and triggers…
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-2026-44844 has been found in eml_parser.
Attackers can target a specific entry point like RecursionError over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade eml_parser to 3.0.1 or later.
If unsure, ask your IT team or search "eml_parser CVE-2026-44844" on the vendor's site.
CVE-2026-44844 (eml_parser) — CWE-674
Attack surface: RecursionError / sys.recursionlimit / _header_value_parser / EmlParser
Patched: 3.0.1 — 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-674) exists in eml_parser. Attackers reach the vulnerable code path via RecursionError.
Check the vendor advisory for the affected versions of eml_parser. Attack surface: RecursionError / sys.recursionlimit / _header_value_parser / EmlParser.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 3.0.1.
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 'eml_parser' . 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
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1Identify exposure identify
grep -r 'eml_parser' . | 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
eml_parser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 eml_parser to 3.0.1ステージング環境で 3.0.1 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
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com