CVE-2026-48850

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Published 2026-05-25 · Modified 2026-05-27

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CVSS v3

5.9

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

5.9

Description

PuTTY 0.72 before 0.84 has a double free in RSA KEX.

Predictions

Exploit likelihood

69%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

Mitigation details

Source: Debian Security Tracker · View original ↗ · DFSG

CVE-2026-48850 NameCVE-2026-48850 DescriptionPuTTY 0.72 before 0.84 has a double free in RSA KEX. SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) Vulnerable and fixed packages The table below lists information on source packages. Source PackageReleaseVersionStatus putty…

CVE-2026-48850

Name	CVE-2026-48850
Description	PuTTY 0.72 before 0.84 has a double free in RSA KEX.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
putty (PTS)	bullseye	0.74-1+deb11u2	vulnerable
	bullseye (security)	0.74-1+deb11u1	vulnerable
	bookworm	0.78-2+deb12u2	vulnerable
	bookworm (security)	0.78-2+deb12u1	vulnerable
	trixie	0.83-3	vulnerable
	sid, forky	0.84-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
putty	source	(unstable)	0.84-1

Notes

[trixie] - putty <no-dsa> (Minor issue)
[bookworm] - putty <no-dsa> (Minor issue)
[bullseye] - putty <postponed> (Minor issue; can be fixed with next upload)
https://lists.tartarus.org/pipermail/putty-announce/2026/000042.html
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/rsakex-double-free.html
Fixed by: https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=ba3ed53e0bf6682f89940bc2c3e83da6b1524024 (0.84)

Home - Debian Security - Source (Git)

Apply commands

text fix

Notes

[trixie] - putty <no-dsa> (Minor issue)[bookworm] - putty <no-dsa> (Minor issue)[bullseye] - putty <postponed> (Minor issue; can be fixed with next upload)https://lists.tartarus.org/pipermail/putty-announce/2026/000042.htmlhttps://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/rsakex-double-free.htmlFixed by: https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=ba3ed53e0bf6682f89940bc2c3e83da6b1524024 (0.84)

OS impact

Debian Mixed 5 releases

Version	Status	Fixed in
trixie	Affected	—
sid	Fixed	`0.84-1`
forky	Fixed	`0.84-1`
bullseye	Affected	—
bookworm	Affected	—

Application impact

Vendor	Product	Versions	Fixed
putty	putty	`{"startIncluding":"0.72","endExcluding":"0.84"}`	`0.84`

References

CWEs

CWE-415

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.