CVE-2026-108555 (CVSS 4.2)

Description

PairDrop through 1.11.2 contains an IP spoofing vulnerability in Peer._setIP that allows remote attackers to join other networks' discovery rooms by supplying a forged cf-connecting-ip header. Attackers who know a victim's public IP can appear as a local device on self-hosted instances not behind Cloudflare to send or receive files.

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CVSS v3.1 Score

4.2

MEDIUM

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

EPSS — Exploit Prediction

0.0014

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-348 CWE-348

References

Other References

https://github.com/schlagmichdoch/PairDrop https://github.com/schlagmichdoch/PairDrop/blob/4862ba3067be1a0f2e0d1e94861dc9200b5bfeea/server/peer.js#L44-L54 https://github.com/schlagmichdoch/PairDrop/blob/4862ba3067be1a0f2e0d1e94861dc9200b5bfeea/server/ws-server.js#L312-L314 https://github.com/schlagmichdoch/PairDrop/issues/510 https://www.vulncheck.com/advisories/pairdrop-through-1.11.2-ip-spoofing-via-cf-connecting-ip-header

Frequently Asked Questions

What is CVE-2026-108555? +

PairDrop through 1.11.2 contains an IP spoofing vulnerability in Peer._setIP that allows remote attackers to join other networks' discovery rooms by supplying a forged cf-connecting-ip header. Attackers who know a victim's public IP can appear as a local device on self-hosted instances not behind Cloudflare to send or receive files. It has a CVSS v3.1 base score of 4.2 (MEDIUM).

How severe is CVE-2026-108555? +

CVE-2026-108555 has a CVSS v3.1 score of 4.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0014, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-108555? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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