VulnerabilityPublished 15 Aug 2026Updated 31 Aug 2026

CVE-2026-73055: ericcornelissen shescape · Improper Encoding or Escaping of Output

Affects ericcornelissen shescapeSource CVE Database V5

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 3.0.2 or 2.1.15 when convenient.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 4.0 base score

6.3Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.0.2, 2.1.15

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

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

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to 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: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable 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 15 Aug 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 13 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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-jfpg-hfv5-2rf7

What to do

Upgrade ericcornelissen shescape to 3.0.2 or 2.1.15.

Affected software

Product	Affected	Fixed in
ericcornelissenshescape	Affected >=3.0.0 <3.0.2	Fixed in 3.0.2
ericcornelissenshescape	Affected <2.1.15	Fixed in 2.1.15
GitHubshescape`pkg:github/shescape`Other threats	Affected <2.1.15 >=3.0.0 <3.0.2	Fixed in 2.1.15 3.0.2

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

AI-suggested

Users should upgrade to versions 2.1.15 or later, or 3.0.2 or later, where this issue is fixed. Until then, avoid passing untrusted input to the escape and escapeAll APIs in assignment contexts on affected shell configurations.

Description

CVE-2026-73055 is a medium severity vulnerability in the ericcornelissen shescape library affecting versions before 2.1.15 and 3.0.0 before 3.0.2. The issue involves improper escaping of tilde (~) characters in assignment contexts on Unix systems where the shell is set to "sh" and /bin/sh points to BusyBox. This can allow an attacker using the escape and escapeAll APIs with untrusted input to inject a tilde payload that discloses the user's home directory location and potentially alters the target location of a command.

Impact

An attacker can use this vulnerability to disclose the user's home directory path and potentially alter the location on which a command operates. This could lead to unintended command execution contexts or information leakage about the environment. The impact is limited to environments where the shell is explicitly set to "sh" and /bin/sh points to BusyBox, and where untrusted input is passed to the affected APIs in assignment contexts.

Summary

The vulnerability in shescape occurs because versions prior to 2.1.15 and 3.0.2 do not properly escape tilde (~) characters in assignment contexts when the shell environment is configured as "sh" and /bin/sh is linked to BusyBox. When untrusted input is passed to the escape or escapeAll APIs in an assignment prefix to a command, an attacker can inject a tilde character that causes disclosure of the user's home directory path and may influence the command's operational context. This improper encoding or escaping flaw can lead to information disclosure and command behavior alteration under specific shell configurations.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Sep 2026, 15:53 UTC

Technical details

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