CVE-2026-112880VulnerabilityPublished 26 Oct 2026

CRLF Injection

Source GCVE Database

Authoritative record:CVE-2026-112880· Low 2.1

Not known to be exploited · CVSS 2.1 Low : upgrade to 4.9.0 when convenient.

Data as of 26 Oct 2026, 17:05 UTC

CVSS 4.0 base score

2.1Low

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 4.9.0, 5ee7d7d19eba27e774667d472feb1e93a08af7f9

CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: Low
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-5qp8-qrjx-2669

What to do

Upgrade hackney to 4.9.0; hackney to 5ee7d7d19eba27e774667d472feb1e93a08af7f9.

Affected software

Product	Affected	Fixed in
benoitchackney	Affected >=2.0.0 <4.9.0	Fixed in 4.9.0
hackneybenoitc/hackney	Affected ≥ 5df5a74a2817d5b12880d217db33253ff1fae1b5, < 5ee7d7d19eba27e774667d472feb1e93a08af7f9	Fixed in 5ee7d7d19eba27e774667d472feb1e93a08af7f9
Hexhackney`pkg:hex/hackney`Other threats	Affected >=2.0.0 <4.9.0	Fixed in 4.9.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Since the vulnerability stems from improper sanitization of the proxy_auth_fun callback return value, users should ensure that this callback does not return untrusted or unsanitized data containing CR, LF, or NUL bytes. Monitor the vendor advisory for official fixes or updates.

Description

CVE-2026-112880 is a vulnerability in the hackney_http_connect module of the benoitc hackney HTTP client library. It allows HTTP Request/Response Splitting due to improper neutralization of CRLF sequences in HTTP headers. Specifically, the proxy_auth_fun callback's return value is inserted into the Proxy-Authorization header without validation, enabling injection of additional header lines if it contains CR, LF, or NUL bytes. This affects hackney versions from 2.0.0 up to but not including 4.9.0.

Impact

An attacker who can influence the proxy_auth_fun callback's return value can inject CRLF sequences into HTTP headers, enabling HTTP Request/Response Splitting attacks. This can lead to HTTP header injection, response splitting, and potentially other HTTP-level attacks depending on the proxy and client behavior. The CVSS 4.0 base score is low (2.1), indicating limited impact and complexity. There is no indication of known exploitation in the wild.

Summary

The vulnerability arises because hackney_http_connect:handle_proxy_auth/11 calls the user-supplied proxy_auth_fun callback after receiving a 407 response from an HTTP CONNECT proxy. The binary data returned by this callback is directly written into the Proxy-Authorization header of the retry request without sanitizing control characters such as carriage return (CR), line feed (LF), or null (NUL) bytes. If the callback derives its return value from untrusted data (e.g., proxy challenge headers), an attacker can inject CRLF sequences to split HTTP headers, leading to HTTP Request/Response Splitting attacks. Other inputs on the CONNECT path are properly checked, but this callback return value is not. The affected versions are hackney from 2.0.0 before 4.9.0.

CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') (opens in a new tab)
Variant weaknessOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.
Implementation · Input Validation
Construct HTTP headers very carefully, avoiding the use of non-validated input data.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. If an input does not strictly conform to specifications, reject it or transform it into something that conforms.
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
HTTP Request Splitting (opens in a new tab)
Accessing/Intercepting/Modifying HTTP Cookies (opens in a new tab)
HTTP Response Splitting (opens in a new tab)
AJAX Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 17:05 UTC

WeaknessesCWE-113

Technical details

References

Community reviews

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