VulnerabilityPublished 13 Aug 2026Updated 26 Oct 2026

CVE-2026-50573: pnpm · Unsafe default behavior breaks integrity check

Affects pnpm@10Source GCVE Database

Not known to be exploited · CVSS 6.8 Medium : upgrade to 10.34.0 when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

6.8Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.34.0

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Aug 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.

What to do

Upgrade pnpm@10 to 10.34.0.

Affected software

Product	Affected	Fixed in
Homebrewpnpm@10`pkg:brew/pnpm%4010`Other threats	Affected >=10.33.2 <10.34.0	Fixed in 10.34.0

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

Description

While it is unclear whether this should be classified as a vulnerability, it is being reported through this channel because the current behavior may represent an unsafe default. ## Summary `pnpm install` in non-frozen mode can accept new remote package content after detecting that the downloaded tarball does not match the integrity recorded in `pnpm-lock.yaml`. When a package is already locked with an `integrity` value, and the registry later serves different metadata and tarball content for the same package name and version, pnpm initially reports an integrity mismatch. However, plain `pnpm install` then performs a resolution repair, accepts the registry's new integrity, updates the lockfile, installs the new content, and exits successfully. This means the lockfile integrity check does not act as a hard stop by default. ## Reproduction Scenario 1. Run a local npm-compatible registry. 2. Publish or serve `example-package@1.0.0` with tarball content `v1`. 3. Install it with pnpm: ```bash pnpm add example-package@1.0.0 --registry=http://127.0.0.1:48741 ``` 4. Confirm `pnpm-lock.yaml` contains the `v1` integrity: ```yaml packages: example-package@1.0.0: resolution: integrity: sha512-...v1... ``` 5. Change the registry metadata and tarball for the same `example-package@1.0.0` to content `v2`. 6. On a clean store/cache, run: ```bash pnpm install --registry=http://127.0.0.1:48741 ``` ## Observed Behavior pnpm detects the checksum mismatch: ```text WARN Got unexpected checksum for "http://127.0.0.1:48741/example-package/-/example-package-1.0.0.tgz". Wanted "sha512-...v1..." Got "sha512-...v2...". ERR_PNPM_TARBALL_INTEGRITY The lockfile is broken! Resolution step will be performed to fix it. ``` However, the install still succeeds: ```text INSTALL_RC=0 INSTALLED=v2-replaced ``` The lockfile is then rewritten to trust the new remote integrity: ```yaml packages: example-package@1.0.0: resolution: integrity: sha512-...v2... ``` ## Expected Behavior If a downloaded tarball does not match the integrity recorded in `pnpm-lock.yaml`, the install should fail by default. The lockfile integrity should be treated as authoritative unless the user explicitly requests lockfile repair or dependency update behavior. ## Security Impact This behavior weakens the protection normally expected from a committed lockfile. If a registry is compromised and an attacker overwrites the metadata and tarball for an existing package version, a new environment without the old pnpm store/cache may install the attacker's replacement package even though the project already has a lockfile with the original integrity. Examples of affected new or clean environments include: - an engineer setting up the project on a new machine - a new team member onboarding to the project In this situation, pnpm first detects that the downloaded tarball does not match the integrity stored in `pnpm-lock.yaml`. However, instead of failing by default, plain `pnpm install` performs a resolution repair, trusts the current remote registry metadata, updates the lockfile to the new integrity, and installs the new registry content. In other words, when the lockfile and registry disagree, the default non-frozen behavior can end up trusting the remote registry over the content previously recorded in the lockfile. This is especially relevant for: - private registries that allow overwriting or republishing the same version - registry mirrors or proxies that can serve changed metadata and tarballs - compromised public or private registries - compromised registry proxy infrastructure The behavior is also surprising because the command reports an integrity error but still exits successfully after resolution repair. This issue does not occur when `--frozen-lockfile` is enabled. In frozen mode, the same integrity mismatch fails the install and does not install the changed package content. However, since the lockfile already records an integrity value, the integrity for the same package version should normally not change. If it does change, one likely explanation is that the server or registry has been compromised or is serving mutated package content. Under normal package publishing workflows, changed package content should be published as a new version instead of replacing an existing version. For that reason, it may be safer for pnpm's default behavior to be closer to frozen mode for this specific case. At minimum, pnpm should not automatically repair the lockfile and trust the registry after an integrity mismatch. It should fail and let the user explicitly decide whether to discard the locked integrity, re-resolve the package from the remote registry, and update the lockfile. ## Comparison In the same scenario, `npm install` with an existing `package-lock.json` fails with `EINTEGRITY` and does not install the changed tarball. `pnpm install --frozen-lockfile` also fails as expected: ```text ERR_PNPM_TARBALL_INTEGRITY ```

References

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