CVE-2026-49756: wojtekmach req · CRLF Injection
Affects wojtekmach reqSource CVE Database V5
Not known to be exploited · CVSS 2.1 Low : upgrade to 0.6.0 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.6.0, 74506ff2c5addf74df85d79dc726e9b2e264a8ba
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade req to 0.6.0; req to 74506ff2c5addf74df85d79dc726e9b2e264a8ba.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| wojtekmachreq | Affected
| Fixed in
|
| wojtekmachreq | Affected
| Fixed in
|
Hexreqpkg:hex/reqOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, avoid forwarding user-controlled filenames, field names, or MIME types through Req.post/2 with form_multipart enabled. Consider sanitizing or validating these inputs to remove CR and LF characters before passing them to the req library.
Description
CVE-2026-49756 is a CRLF injection vulnerability in the wojtekmach req library versions 0.5.3 before 0.6.0. It occurs because Req.Utils.encode_form_part/2 directly interpolates user-supplied name, filename, and content_type values into multipart headers without escaping or stripping CRLF characters. This allows an attacker to inject arbitrary headers or smuggle additional multipart fields by including CR or LF characters in these values, especially when using %File.Stream{} where filenames may contain such characters. The vulnerability enables multipart parameter smuggling in downstream requests.
References
- github.com/wojtekmach/req/security/advisories/GHSA-px9f-whj3-246m (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-49756.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-49756 (opens in a new tab)
- github.com/wojtekmach/req/commit/74506ff2c5addf74df85d79dc726e9b2e264a8ba (opens in a new tab)